diff --git a/a1_swap_mod_packer/i18n/en.json b/a1_swap_mod_packer/i18n/en.json
index c57ccae..9dcfd45 100644
--- a/a1_swap_mod_packer/i18n/en.json
+++ b/a1_swap_mod_packer/i18n/en.json
@@ -75,7 +75,7 @@
   "gui.output.printer.ip": "IP Address",
   "gui.output.printer.access_code": "Access Code",
   "gui.output.printer.serial": "Serial",
-  "gui.output.printer.send.tooltip": "Send the generated 3MF to an A1 printer over LAN and start printing",
+  "gui.output.printer.send.tooltip": "Send the generated 3MF to an A1 printer over LAN and start printing (LAN only — computer and printer must be on the same local network)",
 
   "gui.dialog.individual_batch.title": "Individual Batch Mode",
   "gui.dialog.individual_batch.text": "Individual batch mode treats every input row as a separate build.\n\nExample: if you add 20 single-plate 3MF files and set copies to 5, Build 3MF will create 20 separate packed files. Each output contains only that source file repeated 5 times.\n\nThis is useful for quickly batch-converting many independent 3MF jobs into multi-copy SwapMod packs. It does not combine all input files into one 3MF.",
diff --git a/a1_swap_mod_packer/i18n/zh_CN.json b/a1_swap_mod_packer/i18n/zh_CN.json
index 5157076..76864f9 100644
--- a/a1_swap_mod_packer/i18n/zh_CN.json
+++ b/a1_swap_mod_packer/i18n/zh_CN.json
@@ -75,7 +75,7 @@
   "gui.output.printer.ip": "IP 地址",
   "gui.output.printer.access_code": "访问码",
   "gui.output.printer.serial": "序列号",
-  "gui.output.printer.send.tooltip": "通过局域网将生成的 3MF 发送到 A1 打印机并开始打印",
+  "gui.output.printer.send.tooltip": "通过局域网将生成的 3MF 发送到 A1 打印机并开始打印（仅支持本地局域网，电脑与打印机需在同一网络下）",
 
   "gui.dialog.individual_batch.title": "独立批处理模式",
   "gui.dialog.individual_batch.text": "独立批处理模式将每一行输入作为独立的构建任务。\n\n示例：如果你添加了 20 个单板 3MF 文件并设置份数为 5，点击\"构建 3MF\"将创建 20 个独立的打包文件。每个输出文件仅包含该源文件重复 5 次的内容。\n\n这个功能适用于快速将大量独立的 3MF 作业批量转换为多份数的 SwapMod 包。它不会将所有输入文件合并到一个 3MF 中。",
diff --git a/a1_swap_mod_packer/printer.py b/a1_swap_mod_packer/printer.py
index 08fc4f7..847d117 100644
--- a/a1_swap_mod_packer/printer.py
+++ b/a1_swap_mod_packer/printer.py
@@ -4,6 +4,7 @@ from __future__ import annotations
 from pathlib import Path
 from dataclasses import dataclass
 
+
 @dataclass
 class PrinterConfig:
     """打印机连接配置。"""
@@ -11,32 +12,94 @@ class PrinterConfig:
     access_code: str = ""     # 局域网访问码
     serial: str = ""          # 打印机序列号
 
+
+def check_printer_ready(config: PrinterConfig) -> bool:
+    """检查打印机是否空闲可接收新任务。
+
+    返回 True 表示打印机空闲，False 表示正忙或离线。
+    """
+    from bambulabs_api import Printer as BambuPrinter
+    from bambulabs_api.states_info import GcodeState
+    printer = BambuPrinter(config.ip, config.access_code, config.serial)
+    try:
+        printer.connect()
+        state = printer.get_state()
+        return state == GcodeState.IDLE
+    except Exception:
+        return False
+    finally:
+        printer.disconnect()
+
+
+def _start_print_for_a1(printer, file_name: str, plate_number: int = 1) -> None:
+    """发送打印机开始打印的 MQTT 指令，使用 A1 专用的 sdcard URL 格式。
+
+    bambulabs_api 的 start_print 方法硬编码了 ftp:/// 前缀，
+    这对 A1 不生效。A1 需要 file:///sdcard/ 前缀。
+    本函数绕过 start_print，直接构造正确的 MQTT 载荷。
+    """
+    plate_location = f"Metadata/plate_{int(plate_number)}.gcode"
+    payload = {
+        "print": {
+            "command": "project_file",
+            "param": plate_location,
+            "file": file_name,
+            "bed_leveling": True,
+            "bed_type": "textured_plate",
+            "flow_cali": True,
+            "vibration_cali": True,
+            "url": f"file:///sdcard/{file_name}",
+            "layer_inspect": False,
+            "sequence_id": "10000000",
+            "use_ams": True,
+            "ams_mapping": [0],
+        }
+    }
+    # 调用名称改写后的私有方法发送原始 JSON 荷载
+    printer.mqtt_client._PrinterMQTTClient__publish_command(payload)
+
+
 def send_to_printer(file_path: Path, config: PrinterConfig) -> bool:
-    """将 3MF 文件上传至打印机并开始打印。
+    """将 3MF 文件上传至 A1 打印机并通过局域网开始打印。
+
+    发送前会检查打印机状态；正忙则拒绝发送。
+    ⚠️ 仅支持本地局域网，电脑与打印机必须在同一网络下。
 
     Args:
         file_path: 要发送的 3MF 文件路径
         config: 打印机连接配置
 
     Returns:
-        True 表示成功，False 表示失败
+        True 表示成功
 
     Raises:
         ImportError: bambulabs_api 未安装
-        Exception: 连接或上传失败
+        RuntimeError: 打印机正忙或上传/打印失败
     """
-    # 延迟导入，避免在没有 bambulabs_api 时报错
     from bambulabs_api import Printer as BambuPrinter
+    from bambulabs_api.states_info import GcodeState
+
     printer = BambuPrinter(config.ip, config.access_code, config.serial)
     try:
         printer.connect()
+
+        # 检查打印机是否空闲
+        state = printer.get_state()
+        if state != GcodeState.IDLE:
+            raise RuntimeError(
+                f"打印机当前状态为 {state.value}，"
+                f"无法开始新任务。请等待当前打印完成。"
+            )
+
         file_name = file_path.name
         with open(file_path, "rb") as f:
             import io
             result = printer.upload_file(io.BytesIO(f.read()), file_name)
         if "226" not in result:
             raise RuntimeError(f"上传文件失败: {result}")
-        printer.start_print(file_name, plate_number=1)
+
+        # 使用 A1 专用的 MQTT 指令开始打印，而非内置的 start_print
+        _start_print_for_a1(printer, file_name, plate_number=1)
         return True
     finally:
         printer.disconnect()