The pulse width modulation (PWM) drive plays a pivotal part in the servo driving system. Therefore, the filters become more important in differential mode and common mode for pulse width signal ahead of direct current motors. The filter circuit was built with the WSA38M power amplifier module in a photoelectric inertial stabilized turret. The PWM drive switch frequency was analyzed, which caused motor heating and electromagnetic coupling interference. The electric parameter of LC filter was calculated and the optimization simulation was carried out. The results of test and electromagnetic compatibility experiments show that the optimized electrical performance is excellent, especially the 22 kHz~53 kHz frequency band has less interference to the system, which is easy to meet the overall index requirements, and provides a reliable basis for the control system design.