At present, according to the localization trend of high-speed EMU's manufacturing technology, and under the premise of key technology digestion and absorption of CRH3, the door communication system network topology structure was studied, and then communication interfaces among the door control system, train control unit, diagnostic unit and brake control unit were designed through multifunction vehicle bus (MVB). The door control procedures were optimized, to ensure real time and reliable work of the door system in high speed dynamic operation environment.Though analyzing operation fault,the control logic between the train communication network and the door control system was optimized. Then the hidden trouble of safety was eliminated, and the safety and stability of train running at a high-speed dynamic operating environment were ensured.