With the development of intelligent information technology, the fuzzy neural network (FNN)algorithm is widely used in the industrial control application. At present, the application, which the FNN is used in the PLC, is still few. In view of this status, the design of FNN based on S7-200 PLC is given. The design uses FNN to program with the ladder diagram and instruction sheet in the S7-200, and operates the program in the simulation software. The result meets requirement.