Use the HiFormat video converter and the audio transcoding function that comes with QQ Music.

1. Use HiFormat Video Converter: Install and run the transcoding software and select the corresponding module. Open HiFormat Video Converter, select the "Audio Conversion" function, and add the mflac file that needs to be converted. Set the output format to mp3, select the sound quality you want to convert, confirm the path you want to save, and finally click "Convert All".

2. Use the audio transcoding function that comes with QQ Music: Open QQ Music, click on the "Main Menu" in the upper right corner, select "Audio Transcoding", and click "Add Songs" in the pop-up window , select the mflac file that needs to be converted. In the transcoding options, select the format as mp3 and click "Start Conversion".