The envelope of seismic data carries ultra-low frequency information and can provide an accurate initial model for full waveform inversion without the low frequency. Although envelope inversion uses ultra-low frequency data for inversion, it needs to use the same fine mesh as full waveform inversion with almost the same amount of computation. According to the characteristics of the envelope data, for a given frequency band, the seismic data will change when the frequency moves, but its instantaneous amplitude envelope is constant. Based on this property, we propose a frequency shift objective function to reduce the frequency band of seismic data and derive the corresponding gradient operator. The new method can reduce the calculation of envelope inversion and improve the computational efficiency while maintaining the accuracy. The model test uses the Marmousi model after resampling. We compare the seismic data before and after the frequency shift and analyse the accuracy of the inverted velocity of different frequency shift data which verify the feasibility and effectiveness of the proposed method.