A signal processing method for encoders based on stationary Kalman filter technology is implemented to satisfy the requirements of angular rate prediction of a servo control system. Firstly, the typical structure of a motor system and the composition of an optical encoder for measuring noises are analyzed, and the parametric mathematical model of the motor system and optical encoder is built for stationary Kalman filter design. Then, the uniform parametric design results of stationary Kalman filter are presented by using the model.Under the Matlab/Simulink environment, the simulation model of the motor system, optical encoder and Kalman filter is completed and the universality and filtering effect of parametric stationary Kalman filter are predicted by different parameters. Finally, an experimental platform is built to verify the simulation conclusion, and the filtering performance is measured. The simulation and experiment results show that the parametric stationary Kalman filter is universalizable for motor systems and the adaptive stationary Kalman filter can estimate the angular-rates by using optical encoders.Obtained data indicate that the standard deviation is 0.021 (°)/s and the maximum error can be controlled under 0.06 (°)/s,which can satisfy the requirements of motor control systems for the angular-rate precision.