Abstract: Through the analyses of the algorithm of sliding mode control and the Kalman filter,a compound sliding mode control algorithm was proposed on the basis of the Kalman filter.In order to improve the controller performance of the test machine of automobile clutch centre plate,the proposed algorithm was applied to its electrical control system.The simulation shows that compared with the compound PID(proportion integral differential),this algorithm has high steady accuracy,tracking accuracy and a fast response speed,and the controller with the Kalman filter can eliminate the random noise and the industrial frequency disturbance.The measurement result shows that the testing precisions of displacement and torque for the test machine are ±0.005 mm and ±0.05 N·m,respectively.