摘要：【中文】本发明提供了一种基于智能终端的音频电路及音频播放系统，所述音频电路包括：内置模块，设于一智能终端内，与所述智能终端主板及USB接口连接，接收所述智能终端主板发出的控制信号及音频信号，根据所述控制信号的状态向所述智能终端USB接口转发所述音频信号；外置模块，设于一音箱内，通过所述音箱USB接口与所述智能终端连接，接收所述内置模块转发的音频信号并播放音频。采用上述技术方案后，在所述智能终端USB接口上实现通信功能、充电功能以及音频播放功能的集成，无需额外的音频接口，节省音频硬件接口所需的结构空间；使用外放音箱实现更好的听觉效果。 【EN】The invention provides an audio circuit and an audio playing system based on an intelligent terminal, wherein the audio circuit comprises: the built-in module is arranged in an intelligent terminal, is connected with the intelligent terminal mainboard and the USB interface, receives a control signal and an audio signal sent by the intelligent terminal mainboard, and forwards the audio signal to the intelligent terminal USB interface according to the state of the control signal; the external module is arranged in a sound box, is connected with the intelligent terminal through the sound box USB interface, receives the audio signal forwarded by the internal module and plays audio. After the technical scheme is adopted, the integration of a communication function, a charging function and an audio playing function is realized on the USB interface of the intelligent terminal, an additional audio interface is not needed, and the structural space required by an audio hardware interface is saved; a better hearing effect is achieved using the play-out box.