Rapid thermal cycle injection molding technology with steam heating can solve the defect in routine injection process thoroughly, such as short shot, jetting and weld lines etc, it is widely used in large injection mold with high forming quality requirements. In this paper, temperature control system of rapid thermal cycle injection moulds with steam heating of display shell is designed. First, give the overall dimension of display shell, heating and cooling method and the layout scheme. Second, give the control scheme and control parameter of display shell mold temperature. Last, the hardware, software, temperature control algorithm and human-computer interface of temperature control system is designed detailed after the type of PLC and design software of human-computer are chosen.