A switchable I2S interface including a multiplexer, a switchable FIFO memory and a switchable shift register, is disclosed. The multiplexer receives a transmission instruction or a receiving instruction, and configured to generate a switching signal according to the received instruction. The switchable FIFO memory is connected to the multiplexer and receives the switching signal, and comprise a transmission control circuit and a receiving control circuit. According to the switching signal, the switchable FIFO memory switches on the transmission control circuit to transmit the audio output signal, or switches on the receiving control circuit to receive the audio input signal. The switchable shift register is connected to the switchable FIFO memory, and receives and temporarily stores the audio output signal and the audio input signal.