Abstract: In order to make sure the seeding quality of air-suction seeding system,it is very important to control the vacuum degree of sowing drum.The authors gave a brief introduction about the structure and principles of air-suction seeding system and introduced an automatic control system to control vacuum degree based on the methods of fuzzy control.A layout about two-dimension fuzzy controller was described.According to the dynamic simulation using MATLAB fuzzy toolbox,it is feasible to adopt the fuzzy control method to control the vacuum degree of sowing drum in air-suction seeding system.