Data transmission method based on audio input output interface

The invention relates to a data transmission method based on an audio input output interface and an implementation system of the data transmission method. The method includes: setting power supply manners, and data transmission protocols based on the audio input output interface and adopting differential Manchester encoding for data transmission from an audio output interface. The implementation system of the method comprises a power circuit module, a master control circuit module, a smart phone device connected with the implementation system through the audio input output interface and a magnetic head device for reading data. A smart phone outputs audio alternating current from the audio output interface to power the master control module after the audio alternating current is converted into direct current, the smart phone reads data of external media through the audio input output interface, the master control module and the magnetic head device, and accordingly data communication is achieved. The method and the system are compatible with various types of mobiles phones for read-write of magnetic cards, flexible, light, practical and easy to popularize.