The present disclosure generally relates to the technical field of mobile apparatuses, and discloses a method and a device for an earphone and a USB to share a Micro-USB interface. The method comprises the following steps of: A. detecting whether USB lines or earphone lines are plugged into the Micro-USB interface and generating a corresponding control signal to a control module by an interface detecting module; and B. selecting to activate a USB task or turn on an audio path according to the control signal by the control module. The present disclosure allows the earphone function and the USB function to be achieved through a single Micro-USB interface (i.e., the battery charger, the data lines and the earphone function are integrated together), and can be implemented in a simple structure and at a low cost.