How to get mobile phone music to Xiaomi Bluetooth stereo?

Copy the songs on the mobile phone to the USB flash drive, then unplug the USB flash drive and plug it into Xiaomi's mobile phone, and move the songs to the mobile phone.

Xiaomi has a sensitive sound and can control most household appliances with a remote control. I won't do it if I can say it later. Xiaomi ecosystem is doing really well. The only drawback is that infrared can only be controlled point-to-point, and it will not work if it is shielded. The appearance is relatively small, but the weight is a bit.