Why does Xiaomi's mobile phone automatically play music when it is plugged into headphones?

This is because the function of inserting headphones into the mobile phone to automatically play music is turned on.

Taking Xiaomi 6 mobile phone as an example, the method to turn off this function is as follows:

First turn on Xiaomi 6 mobile phone, then find the "Settings" icon on the desktop of Xiaomi 6 mobile phone, and click Enter.

2. After entering the setting interface of Xiaomi 6 mobile phone, select the option of "headphone cable control".

3. After entering the headphone cable control, find the "plug-in automatic playback" item and close it.