The comprehensive analysis was based on the problems existed in the development of injection molding machine control technology and related patents. Study was carried out in the three main stages of work cycle and injection molding process of the machine, and the main factors affecting surface quality of injection molding products. The key technology of full closed loop control of injection molding machine was proposed from four aspects including bus technology, high speed dynamic response, fuzzy control and electromechanical optimization. The results show that the application layer of NCUCBus bus protocol is redefined in order to realize the control of the pressure, position closedloop control of injection molding machine, high speed dynamic response control and high precision temperature control. The boundary condition of the whole closedloop position control and closedloop pressure control was achieved by using the fuzzy parameters of optimal selfsearching, and the transition switching process was smoother with strong robustness. Three implementation methods are proposed for the optimal control of alternating current (AC) permanent magnet synchronous servo motor: high response bandwidth broadening technology, high rigid disturbance rejection technology, online parameters identification and selfadjusting technology of servo motor, thus enhanced the performance index of the injection molding machine.