The present disclosure provides an audio data processing circuit and an audio data processing method. The audio data processing circuit includes a word select interface, a clock signal interface and an audio data interface. The word select interface is configured to receive a word select signal. The clock signal interface is configured to receive a clock signal, and generating an audio data interface signal according to a number of clocks of the clock signal in one period of the word select signal. The audio data interface is configured to transmit the audio data to a processing unit through a first transmission protocol or a second transmission protocol.