Aircraft design is a complicated and huge system engineering. System suppliers usually submit the proposal of the achitecture and main equipment, and aircraft designers are responsible for system integration. The main functions of interphone system are based on the audio management unit, and aircraft designers need to complete the system integration including the equipment selection. The conectors of interphone system are the plug and jack for audio transmission. The types of jack, mechanical requirements and environmental requirements need to be taken into account while selecting jack. And the connection rules are also considered in order to match the headset and microphone.