With the development of mobile devices, Android systems are becoming increasingly popular. Due to the high cost of NFC chip hardware, a large number of Android devices are not configured, resulting in limitations in the application range of the near field communication by using the NFC chip. In order to solve the general problem of near field communication. This paper introduces a schema which uses speaker and microphone builtin mobile device for the near field communication, presents the design of the prototype APP of Android phone, describes modulationdemodulation algorithm using soniccamplitude modulation to transmit binary information. The program has been tested in terms of compatibility, recognition rate, antiinterference etc. The results show some advantages, like low hardware requirements, economy, reliability. This method has good prospects for application.