Abstract: Corn harvester header reel chain speed lacks automatic control system, which will cause corn stalk to be pushed down．To solve this problem, a reel chain speed control system based on double closed loop PID control was designed with harvester speed as reference value and reel chain speed and torque as feedback value．After calculation of key parameters, the AMESim software was used for system modeling and simulation．Simulation results showed that the maximum step response time of double closed loop PID control system to speed signal was 0.87 s, and the maximum overshoot was 2.63%．When control system was affected by step signal of reel chain resistance torque, the maximum speed drop rate was 6.34%．Power consumption of reel chain system reduced by 5.3% compared with pure mechanical drive．This control method could provide a new idea for design of corn harvester reel chain system．