Self-adaptive CMAC NN was used to adjust the liquid-level of the starch production-line after analyzing and comparing the principle of tradition PID and self-adaptive CMAC NN and a mathematical model about one of liquid-level loop of starch production-line was built, then, a controller was designed and simulated. The simulation results showed that self-adaptive CMAC NN is better than tradition PID on the respect of control effect and its robustness is higher than tradition PID. Real-time level process control system was devised on the basis of xPC Target software environment of Matlab. The rapid prototyping control system could be done easily and the investment is cheap. The period of development could be shortened. This system could realize the accuracy process control. 