diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 29d49576f..dbd63f6f7 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -8,7 +8,7 @@
     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
     <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
     <uses-feature android:name="android.hardware.camera"/>
-    <uses-feature android:name="android.hardware.cacamera.autofocus"/>
+    <uses-feature android:name="android.hardware.camera.autofocus"/>
 
     <!--bugly permission need-->
     <uses-permission android:name="android.permission.INTERNET" />
diff --git a/libausbc/src/main/java/com/jiangdg/ausbc/base/MultiCameraActivity.kt b/libausbc/src/main/java/com/jiangdg/ausbc/base/MultiCameraActivity.kt
index af8572cdc..01d6322eb 100644
--- a/libausbc/src/main/java/com/jiangdg/ausbc/base/MultiCameraActivity.kt
+++ b/libausbc/src/main/java/com/jiangdg/ausbc/base/MultiCameraActivity.kt
@@ -29,20 +29,15 @@ abstract class MultiCameraActivity: BaseActivity() {
     private val mCameraMap = hashMapOf<Int, MultiCameraClient.Camera>()
 
     override fun initData() {
-        mCameraClient = MultiCameraClient(requireContext(), object : IDeviceConnectCallBack {
+        mCameraClient = MultiCameraClient(this, object : IDeviceConnectCallBack {
             override fun onAttachDev(device: UsbDevice?) {
                 device ?: return
-                context?.let {
-                    if (mCameraMap.containsKey(device.deviceId)) {
-                        return
-                    }
-                    MultiCameraClient.Camera(it, device).apply {
-                        mCameraMap[device.deviceId] = this
-                        onCameraAttached(this)
-                    }
-                    if (isAutoRequestPermission()) {
-                        mCameraClient?.requestPermission(device)
-                    }
+                MultiCameraClient.Camera(this@MultiCameraActivity, device).apply {
+                    mCameraMap[device.deviceId] = this
+                    onCameraAttached(this)
+                }
+                if (isAutoRequestPermission()) {
+                    mCameraClient?.requestPermission(device)
                 }
             }
 
@@ -56,10 +51,9 @@ abstract class MultiCameraActivity: BaseActivity() {
             override fun onConnectDev(device: UsbDevice?, ctrlBlock: USBMonitor.UsbControlBlock?) {
                 device ?: return
                 ctrlBlock ?: return
-                context ?: return
                 mCameraMap[device.deviceId]?.apply {
                     setUsbControlBlock(ctrlBlock)
-                    onCameraConnected(this)
+                    onCameraDisConnected(this)
                 }
             }
 
diff --git a/libausbc/src/main/java/com/jiangdg/ausbc/camera/CameraUvcStrategy.kt b/libausbc/src/main/java/com/jiangdg/ausbc/camera/CameraUvcStrategy.kt
index ba1616dd0..0772535aa 100644
--- a/libausbc/src/main/java/com/jiangdg/ausbc/camera/CameraUvcStrategy.kt
+++ b/libausbc/src/main/java/com/jiangdg/ausbc/camera/CameraUvcStrategy.kt
@@ -110,14 +110,8 @@ class CameraUvcStrategy(ctx: Context) : ICameraStrategy(ctx) {
 
     override fun startPreviewInternal() {
         try {
-            createCamera() ?: return
-            realStartPreview() ?: return
-            val dev = mDevSettableFuture?.get().apply {
-                mDevConnectCallBack?.onConnectDev(this)
-            }
-            if (Utils.debugCamera) {
-                Logger.i(TAG, " start preview success!!!, id(${dev?.deviceId})$dev")
-            }
+            createCamera()
+            realStartPreview()
         } catch (e: Exception) {
             stopPreview()
             Logger.e(TAG, " preview failed, err = ${e.localizedMessage}", e)
@@ -212,6 +206,12 @@ class CameraUvcStrategy(ctx: Context) : ICameraStrategy(ctx) {
                     )
                 )
             }
+            val dev = mDevSettableFuture?.get().apply {
+                mDevConnectCallBack?.onConnectDev(this)
+            }
+            if (Utils.debugCamera) {
+                Logger.i(TAG, " start preview success!!!, id(${dev?.deviceId})$dev")
+            }
         } catch (e: Exception) {
             postCameraStatus(CameraStatus(CameraStatus.ERROR, e.localizedMessage))
             Logger.e(TAG, " startPreview failed. err = ${e.localizedMessage}", e)