diff --git a/src/Core/BatchQueueManager.cs b/src/Core/BatchQueueManager.cs
index c7d7ff7..980d626 100644
--- a/src/Core/BatchQueueManager.cs
+++ b/src/Core/BatchQueueManager.cs
@@ -501,6 +501,18 @@ namespace NavisworksTransport.Core
                     LogManager.Info(
                         $"[批处理] 剖面盒自动检测完成: {pathRoute.Name}, 碰撞={detection.TotalCollisions}, " +
                         $"唯一对象={detection.UniqueCollidedObjectsCount}, 对象=[{string.Join(", ", detection.CollidedObjects)}]");
+
+                    // F2：碰撞对象映射（副实例 → 主模型 PathId，按层级链匹配）
+                    int mappedCount = 0;
+                    foreach (var mapping in detection.CollidedObjectMappings)
+                    {
+                        if (!string.IsNullOrWhiteSpace(mapping.MainPathId))
+                        {
+                            mappedCount++;
+                            LogManager.Info($"[F2映射] {mapping.Name}: 副实例={mapping.SecondaryPathId} -> 主模型={mapping.MainPathId}");
+                        }
+                    }
+                    LogManager.Info($"[F2映射] 完成: {mappedCount}/{detection.CollidedObjectMappings.Count} 个碰撞对象映射到主模型");
                     return;
                 }
 
diff --git a/src/Core/PathPlanningManager.cs b/src/Core/PathPlanningManager.cs
index 6fd036c..b01b37a 100644
--- a/src/Core/PathPlanningManager.cs
+++ b/src/Core/PathPlanningManager.cs
@@ -91,6 +91,11 @@ namespace NavisworksTransport
         /// </summary>
         public bool IsToolPluginActive => _isToolPluginActive;
 
+        /// <summary>
+        /// 路径数据库是否已初始化（F1 副实例检测前等待数据库就绪，避免路径导入时数据库未建导致丢失）。
+        /// </summary>
+        public bool IsDatabaseReady => _pathDatabase != null;
+
         /// <summary>
         /// 获取当前是否在预览模式
         /// </summary>
diff --git a/src/Core/Services/SectionBoxBatchDetector.cs b/src/Core/Services/SectionBoxBatchDetector.cs
index 17baef5..e9e5b2e 100644
--- a/src/Core/Services/SectionBoxBatchDetector.cs
+++ b/src/Core/Services/SectionBoxBatchDetector.cs
@@ -50,6 +50,21 @@ namespace NavisworksTransport.Core.Services
             public int TotalFrames { get; set; }
             public string LocalModelPath { get; set; }
             public string ErrorMessage { get; set; }
+
+            /// <summary>
+            /// F2：碰撞对象映射（名称 → 主模型 PathId，按层级链匹配）
+            /// </summary>
+            public List<CollidedObjectMapping> CollidedObjectMappings { get; set; } = new List<CollidedObjectMapping>();
+        }
+
+        /// <summary>
+        /// F2：碰撞对象映射（副实例 → 主模型）。
+        /// </summary>
+        public class CollidedObjectMapping
+        {
+            public string Name { get; set; }
+            public string SecondaryPathId { get; set; }
+            public string MainPathId { get; set; }
         }
 
         private const string DbPathEnvironmentVariable = "TRANSPORTPLUGIN_TEST_DB_PATH";
@@ -106,8 +121,9 @@ namespace NavisworksTransport.Core.Services
 
                 BoundingBox3D bounds = SectionClipHelper.CalculatePathClipBox(adjustedPoints, 4.0, 2.0);
 
-                // 2. 导出局部 NWD（UI 线程：NW API + 导出）
+                // 2. 导出局部 NWD（UI 线程：NW API + 导出）；同时构建盒内对象映射（chain→主PathId，F2 用）
                 bool exported = false;
+                var chainToMainPathId = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
                 try
                 {
                     exported = System.Windows.Application.Current.Dispatcher.Invoke(() =>
@@ -120,6 +136,26 @@ namespace NavisworksTransport.Core.Services
                             return false;
                         }
 
+                        // F2：记录盒内对象映射（层级链去根 → 主模型 PathId）
+                        foreach (ModelItem boxItem in traversal.ObjectsInBox)
+                        {
+                            string chain = BuildAncestorChain(boxItem);
+                            if (string.IsNullOrWhiteSpace(chain))
+                            {
+                                continue;
+                            }
+
+                            try
+                            {
+                                var path = document.Models.CreatePathId(boxItem);
+                                chainToMainPathId[TrimRootFromChain(chain)] = path.PathId;
+                            }
+                            catch
+                            {
+                            }
+                        }
+                        LogManager.Info($"[剖面盒批检测] 盒内对象映射: {chainToMainPathId.Count} 条");
+
                         string exportedPath = exporter.ExportToNwd(document, traversal, localModelPath);
                         return !string.IsNullOrEmpty(exportedPath) && File.Exists(exportedPath);
                     });
@@ -151,6 +187,13 @@ namespace NavisworksTransport.Core.Services
                         return result;
                     }
 
+                    // 等待副实例路径数据库就绪（数据库初始化晚于插件加载，路径导入前必须先建库，否则路径丢失）
+                    if (!await WaitDatabaseReadyAsync(client, TimeSpan.FromSeconds(60)).ConfigureAwait(false))
+                    {
+                        result.ErrorMessage = "副实例路径数据库未就绪（60s 超时）";
+                        return result;
+                    }
+
                     if (!await ImportRouteAsync(client, routeFilePath).ConfigureAwait(false))
                     {
                         result.ErrorMessage = "副实例导入路径失败";
@@ -173,7 +216,8 @@ namespace NavisworksTransport.Core.Services
                     return await RunDetectionAsync(
                         client, route, isVirtualObject, animatedObjectPath,
                         virtualObjectLengthModelUnits, virtualObjectWidthModelUnits,
-                        virtualObjectHeightModelUnits, frameRate, durationSeconds, result).ConfigureAwait(false);
+                        virtualObjectHeightModelUnits, frameRate, durationSeconds, result,
+                        chainToMainPathId).ConfigureAwait(false);
                 }
                 finally
                 {
@@ -298,6 +342,41 @@ namespace NavisworksTransport.Core.Services
             return false;
         }
 
+        /// <summary>
+        /// 等待副实例路径数据库就绪（PathPlanningManager.IsDatabaseReady）。
+        /// 副实例数据库初始化晚于插件加载，路径导入前必须已建库。
+        /// </summary>
+        private static async Task<bool> WaitDatabaseReadyAsync(HttpClient client, TimeSpan timeout)
+        {
+            DateTime deadline = DateTime.UtcNow.Add(timeout);
+            while (DateTime.UtcNow < deadline)
+            {
+                try
+                {
+                    using (var response = await client.GetAsync("/api/test/status").ConfigureAwait(false))
+                    {
+                        if (response.IsSuccessStatusCode)
+                        {
+                            string content = await response.Content.ReadAsStringAsync().ConfigureAwait(false);
+                            JObject payload = JObject.Parse(content);
+                            if (payload.Value<bool?>("ok") == true &&
+                                payload["data"]?["pathManager"]?["isDatabaseReady"]?.Value<bool?>() == true)
+                            {
+                                return true;
+                            }
+                        }
+                    }
+                }
+                catch
+                {
+                }
+
+                await Task.Delay(1000).ConfigureAwait(false);
+            }
+
+            return false;
+        }
+
         private static async Task<bool> ImportRouteAsync(HttpClient client, string routeFilePath)
         {
             string requestUri = "/api/test/import-route-file?path=" + Uri.EscapeDataString(routeFilePath) + "&overwrite=true";
@@ -442,6 +521,37 @@ namespace NavisworksTransport.Core.Services
             return string.Join(" / ", segments.Skip(1).Select(s => s.Trim()));
         }
 
+        /// <summary>
+        /// 构造 ModelItem 的层级链（AncestorsAndSelf 的 DisplayName，'/' 分隔）。
+        /// </summary>
+        private static string BuildAncestorChain(ModelItem item)
+        {
+            try
+            {
+                var segments = new List<string>();
+                var current = item;
+                int guard = 0;
+
+                while (current != null && guard < 15)
+                {
+                    var name = current.DisplayName;
+                    if (!string.IsNullOrWhiteSpace(name))
+                    {
+                        segments.Add(name.Trim());
+                    }
+                    current = current.Parent;
+                    guard++;
+                }
+
+                segments.Reverse();
+                return string.Join(" / ", segments);
+            }
+            catch
+            {
+                return null;
+            }
+        }
+
         private static async Task<DetectionResult> RunDetectionAsync(
             HttpClient client,
             PathRoute route,
@@ -452,7 +562,8 @@ namespace NavisworksTransport.Core.Services
             double objectHeightModelUnits,
             int frameRate,
             double durationSeconds,
-            DetectionResult result)
+            DetectionResult result,
+            Dictionary<string, string> chainToMainPathId)
         {
             // 动画参数从模型单位换算回米（副实例 config 以米存储）
             double metersToModelUnits = UnitsConverter.GetMetersToUnitsConversionFactor();
@@ -501,7 +612,35 @@ namespace NavisworksTransport.Core.Services
                     JArray collided = (JArray)report["collidedObjects"];
                     if (collided != null)
                     {
-                        result.CollidedObjects = collided.Select(t => (string)t).ToList();
+                        foreach (JToken token in collided)
+                        {
+                            JObject obj = (JObject)token;
+                            string name = (string)obj["name"];
+                            if (string.IsNullOrWhiteSpace(name))
+                            {
+                                continue;
+                            }
+
+                            var mapping = new CollidedObjectMapping
+                            {
+                                Name = name,
+                                SecondaryPathId = (string)obj["pathId"]
+                            };
+
+                            // F2：按层级链（去根）查盒内对象映射 → 主模型 PathId
+                            string chain = (string)obj["ancestorChain"];
+                            if (!string.IsNullOrWhiteSpace(chain))
+                            {
+                                string tail = TrimRootFromChain(chain);
+                                if (tail != null && chainToMainPathId != null && chainToMainPathId.TryGetValue(tail, out string mainPathId))
+                                {
+                                    mapping.MainPathId = mainPathId;
+                                }
+                            }
+
+                            result.CollidedObjects.Add(name);
+                            result.CollidedObjectMappings.Add(mapping);
+                        }
                     }
                 }
 
diff --git a/src/Core/Services/TestAutomationHttpService.cs b/src/Core/Services/TestAutomationHttpService.cs
index 5076e67..c9293c3 100644
--- a/src/Core/Services/TestAutomationHttpService.cs
+++ b/src/Core/Services/TestAutomationHttpService.cs
@@ -477,6 +477,7 @@ namespace NavisworksTransport.Core.Services
                 pathManager = new
                 {
                     isAvailable = pathManager != null,
+                    isDatabaseReady = pathManager != null && pathManager.IsDatabaseReady,
                     routeCount = allRoutes?.Count ?? 0,
                     currentRouteId = currentRoute?.Id,
                     currentRouteName = currentRoute?.Name,
@@ -1151,6 +1152,70 @@ namespace NavisworksTransport.Core.Services
             return port;
         }
 
+        /// <summary>
+        /// F2：序列化碰撞对象详情（name + 副实例 PathId + 层级链），
+        /// 供主 NW 按层级链（导出保留树结构，去根一致）映射回主模型。
+        /// </summary>
+        private static List<object> SerializeCollidedObjects(
+            List<CollisionResult> allCollisions, List<string> nameList)
+        {
+            var result = new List<object>();
+            var seen = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+
+            if (allCollisions != null)
+            {
+                foreach (var collision in allCollisions)
+                {
+                    if (collision?.Item2 == null)
+                    {
+                        continue;
+                    }
+
+                    string name = collision.Item2.DisplayName;
+                    if (string.IsNullOrWhiteSpace(name) || !seen.Add(name))
+                    {
+                        continue;
+                    }
+
+                    if (result.Count >= 50)
+                    {
+                        break;
+                    }
+
+                    string pathId = null;
+                    try
+                    {
+                        var path = Autodesk.Navisworks.Api.Application.ActiveDocument.Models.CreatePathId(collision.Item2);
+                        pathId = path.PathId;
+                    }
+                    catch
+                    {
+                    }
+
+                    result.Add(new
+                    {
+                        name,
+                        pathId,
+                        ancestorChain = BuildAncestorNameChain(collision.Item2)
+                    });
+                }
+            }
+
+            // fallback：AllCollisions 无 Item2 引用时退回名字列表
+            if (result.Count == 0 && nameList != null)
+            {
+                foreach (string name in nameList.Take(50))
+                {
+                    if (seen.Add(name))
+                    {
+                        result.Add(new { name, pathId = (string)null, ancestorChain = (string)null });
+                    }
+                }
+            }
+
+            return result;
+        }
+
         private object BuildSelectionPayload()
         {
             Document activeDocument = Autodesk.Navisworks.Api.Application.ActiveDocument;
@@ -1361,10 +1426,8 @@ namespace NavisworksTransport.Core.Services
                                 screenshotCount = report.Screenshots?.Count ?? 0,
                                 resultId = report.ResultId,
                                 routeId = report.RouteId,
-                                // E4：碰撞对象名字列表（用于跨实例报告回传；PathId/位置映射属 F2 阶段）
-                                collidedObjects = report.CollidedObjectsList?.Count > 0
-                                    ? report.CollidedObjectsList.Take(50).ToList()
-                                    : new List<string>()
+                                // F2：碰撞对象详情（name + 副实例 PathId + 层级链），用于跨实例报告映射回主模型
+                                collidedObjects = SerializeCollidedObjects(report.AllCollisions, report.CollidedObjectsList)
                             }
                     };
                 });
diff --git a/src/Utils/UnitsConverter.cs b/src/Utils/UnitsConverter.cs
index 751600c..7ab3463 100644
--- a/src/Utils/UnitsConverter.cs
+++ b/src/Utils/UnitsConverter.cs
@@ -62,10 +62,25 @@ namespace NavisworksTransport.Utils
                     _cachedMetersToUnitsFactor = GetMetersToUnitsConversionFactor(currentUnits);
                 }
             }
-            catch (Exception)
+            catch
             {
-                // 出错时保留上次的有效值（如果有），否则保持 NaN 以暴露错误
-                // 不要设置默认值，避免掩盖问题
+                // 主路径异常时，用显式文档单位兜底（副实例/文档加载瞬间 ActiveDocument.Units 访问可能抛，
+                // 显式访问通常可用；避免缓存长期 NaN 导致尺寸/路径长度全错）
+                try
+                {
+                    var doc = Application.ActiveDocument;
+                    if (doc != null)
+                    {
+                        var currentUnits = doc.Units;
+                        _cachedUnits = currentUnits;
+                        _cachedUnitsToMetersFactor = GetUnitsToMetersConversionFactor(currentUnits);
+                        _cachedMetersToUnitsFactor = GetMetersToUnitsConversionFactor(currentUnits);
+                    }
+                }
+                catch
+                {
+                    // 仍失败则保留上次有效值（或 NaN 暴露错误）
+                }
             }
         }
 
@@ -76,6 +91,17 @@ namespace NavisworksTransport.Utils
         public static double GetUnitsToMetersConversionFactor()
         {
             UpdateCache();
+
+            // 缓存异常（NaN，副实例/文档加载瞬间）时用显式文档单位兜底
+            if (double.IsNaN(_cachedUnitsToMetersFactor))
+            {
+                var doc = Application.ActiveDocument;
+                if (doc != null)
+                {
+                    return GetUnitsToMetersConversionFactor(doc.Units);
+                }
+            }
+
             return _cachedUnitsToMetersFactor;
         }
 
@@ -116,12 +142,24 @@ namespace NavisworksTransport.Utils
         }
 
         /// <summary>
-        /// 获取米转换为Navisworks文档单位的系数
+        /// <summary>
+        /// 获取米转换为文档单位的系数
         /// </summary>
         /// <returns>转换系数（米转换为文档单位）</returns>
         public static double GetMetersToUnitsConversionFactor()
         {
             UpdateCache();
+
+            // 缓存异常（NaN，副实例/文档加载瞬间）时用显式文档单位兜底
+            if (double.IsNaN(_cachedMetersToUnitsFactor))
+            {
+                var doc = Application.ActiveDocument;
+                if (doc != null)
+                {
+                    return GetMetersToUnitsConversionFactor(doc.Units);
+                }
+            }
+
             return _cachedMetersToUnitsFactor;
         }