前提：USB调试都打开了。USB连接方式：MTP。$ lsusb 能看到你的设备。

1，先尝试换一根好一点的usb线

2，还是不行？尝试尝试这些帖子的解决方法：

https://askubuntu.com/questions/632651/adb-devices-command-wont-detect-my-4-4-android-phone

https://stackoverflow.com/questions/15721778/adb-no-devices-found

反正我是按照2折腾半天，没想到回过头换根线就好了。。醉

注：

adb调试平台下载：https://developer.android.com/studio/releases/platform-tools

unlock教程：https://club.huawei.com/thread-4790911-1-1.html

1, install TWRP:https://twrp.me/huawei/huaweihonor4x.html

2, install Magisk：(How to Install Magisk Latest Version 20.4 on Android [Non-Rooted Phones]) :

3, How can I root a Huawei Honor 4X?
 

工具：

9008强刷

https://www.youtube.com/watch?v=W8salW6m-z8

 https://www.shangmayuan.com/a/980fe373230543409536fafd.html

1，dc-unlocker需要破解 

2，octoplus: https://www.youtube.com/watch?v=GeMC_ZtxE98

https://octoplusbox.com/en/download/software/

3, XDA https://forum.xda-developers.com/honor-play/how-to/unlock-bootloader-unofficial-free-t3914658