Audio interface circuit, circuit group, automobile and audio access method

The invention discloses an audio interface circuit, and the circuit comprises an input end, a main output end, an auxiliary output end, a first filtering module, a first conversion module, a second filtering module and a second conversion module. The first filtering module is used for filtering the differential signal accessed from the input end and outputting the differential signal to the firstconversion module; the first conversion module converts the signal into a first common-mode signal and outputs the first common-mode signal to the second filtering module; the first conversion moduleoutputs the first common-mode signal through the main output end; the second filtering module filters the first common-mode signal to obtain a second common-mode signal, and outputs the second common-mode signal to the second conversion module; and the second conversion module converts the second common-mode signal into a differential signal and outputs the differential signal through the auxiliary output end. The invention also discloses an audio interface circuit group, an automobile and an audio access method, which can effectively improve the signal quality of the same sound source sharedby multiple paths of vehicle-mounted equipment.