diff --git a/src/CounterDrone.Core/Algorithms/DefaultDefensePlanner.cs b/src/CounterDrone.Core/Algorithms/DefaultDefensePlanner.cs
index 18d6267..ea7a334 100644
--- a/src/CounterDrone.Core/Algorithms/DefaultDefensePlanner.cs
+++ b/src/CounterDrone.Core/Algorithms/DefaultDefensePlanner.cs
@@ -411,12 +411,23 @@ namespace CounterDrone.Core.Algorithms
             var mid = ThreatMidpoint(threat);
             var (effectiveR, expansionTime) = ComputeEffectiveRadius(threat, ammo, env);
 
-            float recommendedTiming = threat.ArrivalTime - expansionTime;
-            if (recommendedTiming < 0.1f) recommendedTiming = 0.1f;
-
             float tx = mid.X + targetOffset;
             float tz = mid.Z;
 
+            // 按目标点位置计算无人机到达时间，非中点
+            float droneSpeed = (float)threat.Target.TypicalSpeed / 3.6f;
+            float startX = (float)threat.Waypoints[0].PosX;
+            float startZ = (float)threat.Waypoints[0].PosZ;
+            float endX = (float)threat.Waypoints[^1].PosX;
+            float endZ = (float)threat.Waypoints[^1].PosZ;
+            float totalDist = Kinematics.Distance2D(startX, startZ, endX, endZ);
+            float distToTx = Kinematics.Distance2D(startX, startZ, tx, tz);
+            // 如果目标点在航路反向，截断到 [0, totalDist]
+            distToTx = Math.Max(0, Math.Min(totalDist, distToTx));
+            float txArrival = totalDist > 0.1f ? distToTx / Math.Max(0.1f, droneSpeed) : 0;
+            float recommendedTiming = txArrival - expansionTime;
+            if (recommendedTiming < 0.1f) recommendedTiming = 0.1f;
+
             float fireTime;
             if (unit.Type == PlatformType.AirBased)
             {