Permanent magnet synchronous generator is directly connected with PWM converter in the wind power system based on direct-driven permanent magnet synchronous generator, which results in the increase of the stator losses of the permanent magnet synchronous generator, and even leads to the irreversible demagnetization of permanent magnet materials. To solve this problem, this paper analyzed the influence of amplitude modulation radio and frequency modulation radio on eddy current losses and stator losses of permanent magnet synchronous generator under SVPWM modulation. Finally, this paper compared the results of AnSoft simulation and Fourier analysis with the results obtained from the calculation models of this paper, which verifies the correctness of the calculation model proposed. The calculation models presented have reference value for setting proper amplitude modulation radio and frequency modulation radio under SVPWM modulation. This can ensure the safe operation of the permanent magnet synchronous generator.