diff --git a/src/core/System.cpp b/src/core/System.cpp
index 580bb46..a50a927 100644
--- a/src/core/System.cpp
+++ b/src/core/System.cpp
@@ -520,6 +520,20 @@ void System::processCollisions(
             broadcastVehicleCommand(cmd);
             controllableVehicles_.sendCommand(vehicleId, cmd);
 
+            // ALERT 后立即补发 PARKING 作为停止指令
+            if (cmd.type == CommandType::ALERT) {
+                VehicleCommand parkingCmd = cmd;
+                parkingCmd.type = CommandType::PARKING;
+                parkingCmd.reason = CommandReason::PARKING_SIDE;
+                parkingCmd.timestamp = std::chrono::duration_cast<std::chrono::milliseconds>(
+                    std::chrono::system_clock::now().time_since_epoch())
+                    .count();
+
+                broadcastVehicleCommand(parkingCmd);
+                controllableVehicles_.sendCommand(vehicleId, parkingCmd);
+                Logger::info("ALERT 后补发停车指令到车辆: ", vehicleId);
+            }
+
             // 更新风险记录
             currentVehiclesWithRisk.insert(vehicleId);
             vehicleMaxRiskLevels[vehicleId] = risk.level;
@@ -866,6 +880,20 @@ bool System::handleSafetyZoneRisk(const Vehicle& vehicle,
     broadcastVehicleCommand(cmd);
     controllableVehicles_.sendCommand(vehicle.id, cmd);
 
+    // 安全区触发 ALERT 时也补发 PARKING 作为停止指令
+    if (cmd.type == CommandType::ALERT) {
+        VehicleCommand parkingCmd = cmd;
+        parkingCmd.type = CommandType::PARKING;
+        parkingCmd.reason = CommandReason::PARKING_SIDE;
+        parkingCmd.timestamp = std::chrono::duration_cast<std::chrono::milliseconds>(
+            std::chrono::system_clock::now().time_since_epoch())
+            .count();
+
+        broadcastVehicleCommand(parkingCmd);
+        controllableVehicles_.sendCommand(vehicle.id, parkingCmd);
+        Logger::info("安全区 ALERT 后补发停车指令到车辆: ", vehicle.id);
+    }
+
     CollisionRisk risk;
     risk.id1 = vehicle.id;
     risk.id2 = target ? target->id : "";
@@ -947,4 +975,4 @@ void System::processPushedTrafficLightData(const nlohmann::json& di_data) {
     } catch (const std::exception& e) {
         Logger::error("处理推送的交通信号灯数据时出错: ", e.what());
     }
-}
\ No newline at end of file
+}
diff --git a/src/network/HTTPClient.cpp b/src/network/HTTPClient.cpp
index 2db3273..362d6c8 100644
--- a/src/network/HTTPClient.cpp
+++ b/src/network/HTTPClient.cpp
@@ -97,10 +97,11 @@ bool HTTPClient::sendCommand(const std::string& host, int port, const std::strin
         {"longitude", command.longitude}
     };
 
-    if (command.type == CommandType::SIGNAL) {
-        request["signalState"] = getSignalStateString(command.signalState);
-        request["intersectionId"] = command.intersectionId;
-    }
+    // 字段完整性：即使非 SIGNAL 也保留字段，使用占位值避免后端校验失败
+    request["signalState"] =
+        command.type == CommandType::SIGNAL ? getSignalStateString(command.signalState) : "";
+    request["intersectionId"] =
+        command.type == CommandType::SIGNAL ? command.intersectionId : "";
 
     // 后端当前校验要求该字段始终存在；对非 ALERT/WARNING 场景默认填 0
     request["relativeSpeed"] = command.relativeSpeed;
@@ -174,4 +175,4 @@ bool HTTPClient::sendCommand(const std::string& host, int port, const std::strin
         Logger::error("Command failed with HTTP code: ", http_code, " response: ", response_buffer_);
         return false;
     }
-}
\ No newline at end of file
+}