The present invention is related to a bilateral control system and method of a vehicle-use front seat audio device and a back seat entertainment device according to the present invention, the system includes a vehicle-use front seat audio device, a back seat entertainment device and a connection cable, the control method is provided to copy the signals and pictures of the vehicle-use front seat audio device or the back seat entertainment device and transmit mutually by utilizing the connection cable as the bilateral transmission passageway, the signals and pictures may be mutually bilateral controlled and transmitted via the connection cable by controlling the physical keys or operating on the touch panel.