Abstract：Active magnetic bearing system with redundant sensors was constructed. Five degree of freedom simulation model based on ADAMS and MATLAB was established, and influence of sensor location on dynamic characteristics of the system was analyzed. Incomplete differential PID and fuzzy-PID control programs based on TMS32028335 DSP were compiled. Diagnostic method of sensor fault was designed. Proof tests were implemented by means of cutting sensor cable artificially. Results show that the system can run safely after one of the sensors is damaged.