The interferometer used in traditional Fourier Transform Infrared Spectroscopic Imaging（FTIR）equipment is large in size，and the Variable Gap Fabry Perot interferometer（F-P interferometer）solves the problem of miniaturization of the traditional FTIR equipment with the advantage of its small size and compactness. However，because the internal optical lenses of the F-P interferometer need to be tightly fitted together during installation，the fastening force may locally exert force on the lenses，causing deformation of the lenses and thus affecting the accuracy of the spectral data obtained. Taking a certain type of infrared imaging spectroscopy equipment based on a variable gap F-P interferometer as an example，the deformation of the F-P interferometer lens is measured by a Zygo laser interferometer，and a simulation model of the deformation of the interferometer is established. Through the analysis of the simulation model，it is clarified that the deformation of the F-P interferometer will lead to the degradation of the spectral response intensity and wavelength accuracy，which points out the direction for the subsequent structural optimization design of the F-P cavity.