A processing method and a processing system of an audio multichannel output speaker and a mobile phone are disclosed. The method includes: retrieving an audio and video file and establishing four channel signals for audio signals in the audio and video file with independent channel indications; performing frequency-division processing on the four channel signals respectively, and storing data of the four channel signals after frequency-division processing in order; performing digital-to-analog conversion on the data of the four channel signals respectively, and respectively sending converted analog signal data to speakers corresponding to the four channel signals one-to-one.