1.从Android官方网站下载SDK平台工具

Windows平台的SDK平台工具： https://dl.google.com/android/repository/platform-tools-latest-windows.zip?hl=zh-cn  

2.进入bootloader

adb reboot bootloader

3.bootloader解锁

fastboot flashing unlock

以下是命令执行及反馈信息：

PS C:\Users\Administrator> cd ‘D:\OnePlus 12\platform-tools\’

PS D:\OnePlus 12\platform-tools> .\adb.exe devices -l

* daemon not running; starting now at tcp:5037

* daemon started successfully

b2fb92f9               device product:PJD110 model:PJD110 device:OP5929L1 transport_id:2

PS D:\OnePlus 12\platform-tools> .\adb.exe reboot bootloader

PS D:\OnePlus 12\platform-tools> .\fastboot.exe flashing unlock

OKAY [  0.028s]

Finished. Total time: 0.029s

参考资料：

一加社区@Athena： https://bbs.oneplus.com/thread/1569329088689078278