An audio transmission system and an audio processing method thereof are disclosed. The audio transmission system includes a wireless communication module, a sound receiving module, a memory module, a sound adjustment module, and an output module. The wireless communication module is used for receiving a wireless communication signal or a wireless audio signal from an electronic device. The sound receiving module is used for receiving an ambient sound signal. The memory module stores a first parameter, a second parameter, and a third parameter. The sound adjustment module adjusts the received wireless communication signal, the wireless audio signal, or the ambient sound signal according to the first parameter, the second parameter, or the third parameter so as to generate an adjusted sound signal. The output module is used for outputting the adjusted sound signal.