Abstract: The invention provides a motor nonlinear system modeling method including steps of: obtaining a chirp signal of a first frequency band, and a chirp signal of a second frequency band; exciting the motor by using the chirp signal; obtaining a higher harmonic frequency response of the first frequency band; exciting the motor by using the chirp signal of the second frequency band; obtaining a higher harmonic frequency response of the second frequency band; obtaining a higher harmonic frequency response by splicing the higher harmonic frequency response of the first frequency band and the higher harmonic frequency response of the second frequency band in the frequency domain. The higher harmonic frequency response of the working frequency of the motor is a nonlinear system model of the motor. By virtue of the method provided by the present invention, the accuracy of motor modeling is effectively improved.