diff --git a/mpmaster/src/main/java/com/xypower/mpmaster/AppMaster.java b/mpmaster/src/main/java/com/xypower/mpmaster/AppMaster.java
index e9fa2b59..81b991b0 100644
--- a/mpmaster/src/main/java/com/xypower/mpmaster/AppMaster.java
+++ b/mpmaster/src/main/java/com/xypower/mpmaster/AppMaster.java
@@ -5,6 +5,7 @@ import android.content.Intent;
 import android.net.ConnectivityManager;
 import android.net.Network;
 import android.net.NetworkInfo;
+import android.os.Build;
 import android.os.Environment;
 import android.os.PowerManager;
 import android.os.SystemClock;
@@ -39,6 +40,10 @@ import java.io.OutputStreamWriter;
 import java.net.HttpURLConnection;
 import java.net.URL;
 import java.net.URLEncoder;
+import java.nio.file.CopyOption;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardCopyOption;
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
 import java.util.Date;
@@ -64,6 +69,7 @@ public class AppMaster {
     public static final String CMD_UPDATE_CONFIG = "upd_cfg";
     public static final String CMD_PULL_FILE = "pull_files";
     public static final String CMD_PUSH_FILE = "push_file";
+    public static final String CMD_DOWNLOAD_FILE = "dl_file";
     public static final String CMD_DELETE_FILE = "del_file";
     public static final String CMD_HOT_SPOT = "yw_cmd_hot_spot";
     public static final String CMD_ENABLE_GPS = "yw_cmd_enable_gps";
@@ -185,13 +191,14 @@ public class AppMaster {
         }).start();
     }
 
-    private void runImpl() {
+    private boolean runImpl() {
         String masterUrl = mMasterUrl;
 
         if (TextUtils.isEmpty(masterUrl)) {
-            return;
+            return false;
         }
 
+        boolean res = false;
         HttpURLConnection httpURLConnection = null;
         InputStream inputStream = null;
         Date now = new Date();
@@ -209,15 +216,6 @@ public class AppMaster {
                 masterUrl += "?" + MicroPhotoContext.MASTER_URL_CMDID + "=" + URLEncoder.encode(mCmdid, "UTF-8");
             }
             URL url = new URL(masterUrl);
-            httpURLConnection = (HttpURLConnection) url.openConnection();
-            httpURLConnection.setConnectTimeout(15000);
-            httpURLConnection.setReadTimeout(15000);
-            httpURLConnection.setRequestMethod("POST");
-            // httpURLConnection.setRequestProperty("Connection", "Keep-Alive");
-            httpURLConnection.setDoInput(true);
-            httpURLConnection.setDoOutput(true);
-
-            httpURLConnection.setRequestProperty("Accept-Cmds", "Multiple");
 
             List<Pair<String, String>> postParams = new ArrayList<>();
             postParams.add(new Pair<String, String>("id", mCmdid));
@@ -268,22 +266,56 @@ public class AppMaster {
                 ex.printStackTrace();
             }
 
-            // postParams(httpURLConnection.getOutputStream(), postParams);
-            buildParams(httpURLConnection.getOutputStream(), postParams);
-            httpURLConnection.connect();
-            inputStream = httpURLConnection.getInputStream();
+            for (int idx = 0; idx < 3; idx++) {
+                try {
+                    httpURLConnection = (HttpURLConnection) url.openConnection();
+                    httpURLConnection.setConnectTimeout(15000);
+                    httpURLConnection.setReadTimeout(15000);
+                    try {
+                        httpURLConnection.setRequestMethod("POST");
+                    } catch (Exception ex) {
+                        ex.printStackTrace();
+                    }
+                    // httpURLConnection.setRequestProperty("Connection", "Keep-Alive");
+                    httpURLConnection.setDoInput(true);
+                    httpURLConnection.setDoOutput(true);
+
+                    httpURLConnection.setRequestProperty("Accept-Cmds", "Multiple");
 
-            int responseCode = httpURLConnection.getResponseCode();
+                    // postParams(httpURLConnection.getOutputStream(), postParams);
+                    buildParams(httpURLConnection.getOutputStream(), postParams);
+                    httpURLConnection.connect();
+                    inputStream = httpURLConnection.getInputStream();
 
-            if (responseCode == HttpURLConnection.HTTP_OK) {
-                //在子线程中不能操作UI线程，通过handler在UI线程中进行操作
-                // handler.sendEmptyMessage(0x00);
-                String response = convertStreamToString(inputStream);
-                process(response);
+                    int responseCode = httpURLConnection.getResponseCode();
+
+                    if (responseCode == HttpURLConnection.HTTP_OK) {
+                        //在子线程中不能操作UI线程，通过handler在UI线程中进行操作
+                        // handler.sendEmptyMessage(0x00);
+                        String response = convertStreamToString(inputStream);
+                        process(response);
+                    }
+                    res = true;
+                } catch (Exception ex) {
+                    // ex.printStackTrace();
+                    mService.logger.warning(ex.getMessage());
+                }
+
+                if (res) {
+                    break;
+                }
+
+                try {
+                    Thread.sleep(3000);
+                } catch (Exception ex) {
+
+                }
             }
         } catch (Exception e) {
             e.printStackTrace();
         }
+
+        return res;
     }
 
     private void buildStats(long startTime, List<Pair<String, String>> stats) {
@@ -525,6 +557,44 @@ public class AppMaster {
                     }
                 }
             }
+        }  else if (TextUtils.equals(cmd, CMD_DOWNLOAD_FILE)) {
+
+            String path = jsonObject.optString("path", null);
+            String url = jsonObject.optString("url", null);
+            mService.logger.warning("Recv Download File: " + url + " => " + path);
+
+            File file = new File(path);
+            File parentPath = file.getParentFile();
+            if (!parentPath.exists()) {
+                parentPath.mkdirs();
+            }
+
+            FileDownloader dl = new FileDownloader();
+            File tmpPath = new File(MicroPhotoContext.buildAppDir(mService.getApplicationContext()), "tmp");
+            if (!tmpPath.exists()) {
+                tmpPath.mkdirs();
+            }
+
+            File tmpFile = new File(tmpPath, file.getName());
+            if (tmpFile.exists()) {
+                tmpFile.delete();
+            }
+            String apkPath = file.getAbsolutePath();
+            if (dl.download(url, tmpFile.getAbsolutePath())) {
+                sendResult(cid, 1, cmd, cmd + ":" + mCmdid);
+                Context context = mService.getApplicationContext();
+                mService.logger.info("Downloaded File: " + url);
+
+                try {
+                    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+                        Files.move(tmpFile.toPath(), file.toPath(), StandardCopyOption.REPLACE_EXISTING);
+                    }
+                } catch (Exception ex) {
+
+                }
+            } else {
+                mService.logger.warning("Failed to Download:" + url);
+            }
         } else if (TextUtils.equals(cmd, CMD_HOT_SPOT)) {
             int enable = jsonObject.optInt("enable", 1);
             String name = jsonObject.optString("name", "XYMP");