This paper presents a FPGAbased device precision intermediate frequency (IF) bipolar PWM signal generator PWM drive signal to solve the contradiction between the accuracy and the carrier frequency cannot be balanced in DSP chip. The PWM signal generator using VHDL language to be realized, with high integration, strong antijamming capability, the frequency range of the intermediate frequency can be adjusted without changing the accuracy of PWM. Simulation results show that in the IF, the PWM signal generator can easily change the frequency of the PWM drive signal, and its accuracy will not change. In the experiment a long pulse laser driver circuit, the PWM signal generator PWM good solution to the conflict between precision and frequency, and has strong antijamming capability.