In the process of remote monitoring, the emission wavelength of the laser listener has a nonlinear shift problem, which results in a large displacement deviation between the received beat signal wavelength and the actual beat signal wavelength. A wavelength offset correction method of laser interceptor based on nonlinear function polynomial fitting is proposed. Through the nonlinear estimation of the laser listener wavelength, the offset of the beat frequency signal is identified, and the nonlinear calibration function model is established by using improved polynomial fitting. The center wavelength of each transmitted wave is obtained by power weighting, the actual beat frequency is obtained according to the relationship between the center wave and the voltage change, and the instantaneous beat frequency is calculated by Hilbert transform. The difference between the two is the beat frequency offset. Correct the offset to complete the wavelength nonlinear calibration of the laser listener. The experimental results show that the proposed calibration method effectively reduces the mean square error value of the received wavelength of the laser listener, and the calibrated wavelength is basically consistent with the actual wavelength of the target object, which accurately realizes the wavelength offset correction of the laser listener and improves the accuracy of the laser listener.