The static excitation system with the thyristor widely used in large generators may cause the higher amplitude high frequency shaft voltage pulse. High frequency shaft voltage pulse has become one of the main problems that affect the safe and reliable operation of large generator. The field measurement results of the 1000MW generator shaft voltage are analyzed, and the simulation model of the large static excitation generator shaft voltage based on MATLAB simulink power system is established. It is concluded that the fundamental frequency and its odd harmonics of the common mode voltage output by the static excitation system are the key points for the prevention and control of the shaft voltage of large turbo generator. A tuned filter reducing the shaft current of 1000MW generator with static exciter is presented in this paper. The simulation results show that the filter has good effect on reducing the selected high frequency shaft current.