diff --git a/MiGu.Server/Wms/WmsService.cs b/MiGu.Server/Wms/WmsService.cs
index 065eb4d..9160a54 100644
--- a/MiGu.Server/Wms/WmsService.cs
+++ b/MiGu.Server/Wms/WmsService.cs
@@ -499,7 +499,14 @@ public sealed class WmsService
         });
 
         await AddContainerMoveEventAsync(req.ContainerId, fromStorageId, toStorageId, actor, req.Reason.TrimOr(""), now);
-        await _db.SaveChangesAsync();
+        try
+        {
+            await _db.SaveChangesAsync();
+        }
+        catch (DbUpdateException ex) when (IsUniqueConstraintViolation(ex))
+        {
+            throw new InvalidOperationException("目标库位已被其他容器占用，库位与容器为 1 对 1");
+        }
         await SyncOccupancyStatus(containerId: req.ContainerId, storageId: fromStorageId);
         await SyncOccupancyStatus(storageId: toStorageId);
         return current;
@@ -857,6 +864,20 @@ public sealed class WmsService
             throw new InvalidOperationException("数据已被其他用户修改，请刷新后重试");
     }
 
+    private static bool IsUniqueConstraintViolation(DbUpdateException ex)
+    {
+        for (Exception? e = ex; e != null; e = e.InnerException)
+        {
+            var msg = e.Message;
+            if (msg.Contains("UNIQUE constraint failed", StringComparison.OrdinalIgnoreCase)
+                || msg.Contains("unique index", StringComparison.OrdinalIgnoreCase)
+                || msg.Contains("duplicate key", StringComparison.OrdinalIgnoreCase))
+                return true;
+        }
+
+        return false;
+    }
+
     private static void EnsureUnlocked(EntityBase entity)
     {
         if (entity.IsLock) throw new InvalidOperationException("数据已锁定，不能修改");
diff --git a/MiGu.Server/Wms/WmsTransportPlanner.cs b/MiGu.Server/Wms/WmsTransportPlanner.cs
index 1dee59b..e01e3bd 100644
--- a/MiGu.Server/Wms/WmsTransportPlanner.cs
+++ b/MiGu.Server/Wms/WmsTransportPlanner.cs
@@ -69,8 +69,11 @@ public sealed class WmsTransportPlanner
             .Where(x => x.LocationType == ContainerLocationTypes.Storage).ToListAsync();
         var materials = await _db.Materials.AsNoTracking().Where(x => x.Enabled).ToListAsync();
         var containerMaterials = await _db.ContainerMaterials.AsNoTracking().ToListAsync();
+        var now = DateTimeOffset.UtcNow;
         var activeReservations = await _db.WmsTransportReservations.AsNoTracking()
-            .Where(x => x.Status == WmsReservationStatuses.Active).ToListAsync();
+            .Where(x => x.Status == WmsReservationStatuses.Active
+                        && (x.ExpiresAt == null || x.ExpiresAt > now))
+            .ToListAsync();
         var activeTasks = await _db.WmsTransportTasks.AsNoTracking()
             .Where(x => WmsTransportTaskStatuses.Active.Contains(x.Status)).ToListAsync();
 
diff --git a/MiGu.Server/Wms/WmsTransportTaskService.cs b/MiGu.Server/Wms/WmsTransportTaskService.cs
index d4ff880..64bfb34 100644
--- a/MiGu.Server/Wms/WmsTransportTaskService.cs
+++ b/MiGu.Server/Wms/WmsTransportTaskService.cs
@@ -165,10 +165,27 @@ public sealed class WmsTransportTaskService
 
     public async Task<WmsTransportTask> DispatchAsync(Guid taskId, string actor)
     {
-        var task = await FindTaskAsync(taskId);
-        if (task.Status != WmsTransportTaskStatuses.Reserved)
-            throw new InvalidOperationException("只有 Reserved 状态的任务可以下发");
+        // 原子抢占：仅一条 Reserved 且未在下发中的任务能进入 Dispatching，避免双发
+        var now = DateTimeOffset.UtcNow;
+        var claimed = await _db.WmsTransportTasks
+            .Where(x => x.Id == taskId
+                        && x.Status == WmsTransportTaskStatuses.Reserved
+                        && x.DispatchStatus != "Dispatching"
+                        && x.DispatchStatus != "Dispatched")
+            .ExecuteUpdateAsync(s => s
+                .SetProperty(x => x.DispatchStatus, "Dispatching")
+                .SetProperty(x => x.UpdatedAt, now)
+                .SetProperty(x => x.UpdatedBy, actor));
 
+        if (claimed == 0)
+        {
+            var existing = await FindTaskAsync(taskId);
+            if (existing.Status != WmsTransportTaskStatuses.Reserved)
+                throw new InvalidOperationException("只有 Reserved 状态的任务可以下发");
+            throw new InvalidOperationException("任务正在下发中，请勿重复操作");
+        }
+
+        var task = await FindTaskAsync(taskId);
         var source = await _db.Storages.AsNoTracking().FirstAsync(x => x.Id == task.SourceStorageId);
         var target = await _db.Storages.AsNoTracking().FirstAsync(x => x.Id == task.TargetStorageId);
         var container = await _db.Containers.AsNoTracking().FirstAsync(x => x.Id == task.ContainerId);
@@ -194,14 +211,36 @@ public sealed class WmsTransportTaskService
         return task;
     }
 
+    private async Task ExpireStaleReservationsAsync()
+    {
+        var now = DateTimeOffset.UtcNow;
+        var rows = await _db.WmsTransportReservations
+            .Where(x => x.Status == WmsReservationStatuses.Active
+                        && x.ExpiresAt != null
+                        && x.ExpiresAt < now)
+            .ToListAsync();
+        if (rows.Count == 0) return;
+
+        foreach (var row in rows)
+            row.Status = WmsReservationStatuses.Expired;
+        await _db.SaveChangesAsync();
+    }
+
     private async Task EnsureNoActiveReservationAsync(Guid containerId, Guid targetStorageId)
     {
+        await ExpireStaleReservationsAsync();
+
+        var now = DateTimeOffset.UtcNow;
         if (await _db.WmsTransportReservations.AnyAsync(x =>
-                x.Status == WmsReservationStatuses.Active && x.ContainerId == containerId))
+                x.Status == WmsReservationStatuses.Active
+                && (x.ExpiresAt == null || x.ExpiresAt > now)
+                && x.ContainerId == containerId))
             throw new InvalidOperationException("容器已被其他任务预占");
 
         if (await _db.WmsTransportReservations.AnyAsync(x =>
-                x.Status == WmsReservationStatuses.Active && x.TargetStorageId == targetStorageId))
+                x.Status == WmsReservationStatuses.Active
+                && (x.ExpiresAt == null || x.ExpiresAt > now)
+                && x.TargetStorageId == targetStorageId))
             throw new InvalidOperationException("目标库位已被其他任务预占");
     }