For the reaction process in the continuous stirred tank reactor, the continuous stirred tank reactor (CSTR) in multifunction process and experiment system is utilized to design the control system. The ratio control is adopted for flow, and the cascade control is utilized for level. Besides, the process of rising temperature is controlled via fuzzy predictive method, and the stage of constant temperature is controlled by using fuzzy immunity PID mehtod. Moroever, safety interlock control for pressure is also designed. The above project is implemented by means of SIMATIC PCS7, which attain better control performance, security, and feasibility.