diff --git a/src/Core/Services/SectionBoxBatchDetector.cs b/src/Core/Services/SectionBoxBatchDetector.cs
index 8289071..31fbf01 100644
--- a/src/Core/Services/SectionBoxBatchDetector.cs
+++ b/src/Core/Services/SectionBoxBatchDetector.cs
@@ -215,6 +215,27 @@ namespace NavisworksTransport.Core.Services
                 }
                 result.LocalModelPath = localModelPath;
 
+                // 启动副实例前文件校验（NW 加载失败会弹原生错误窗口，插件无法拦截）：
+                // 1) 文件存在且非空；2) 未被其他进程占用（残留副实例可能仍持有导出文件）
+                var exportFileInfo = new FileInfo(localModelPath);
+                if (!exportFileInfo.Exists || exportFileInfo.Length == 0)
+                {
+                    result.ErrorMessage = $"导出模型文件无效（不存在或为空）: {localModelPath}";
+                    return result;
+                }
+
+                try
+                {
+                    using (var probe = new FileStream(localModelPath, FileMode.Open, FileAccess.ReadWrite, FileShare.None))
+                    {
+                    }
+                }
+                catch (IOException)
+                {
+                    result.ErrorMessage = $"导出模型文件被占用（可能有残留副实例进程未退出），请检查残留 Roamer 进程后重试: {localModelPath}";
+                    return result;
+                }
+
                 // 3. 导出路径文件（JSON，副实例导入用）
                 new PathDataManager().ExportToJson(new List<PathRoute> { route }, routeFilePath);