The spectropolarimetric imaging system based on three photoelastic modulators and one acousto-optic tunable filter (AOTF), has many components, limited field angle of AOTF and uneven spectral distribution in one image. To overcome the disadvantages, an optical imaging system is reported, in which the front optical system is composed of convex lens, concave lens and convex lens. The field angle of measured target is compressed so as to satisfy the requirement of the AOTF field angle. The parallel incident light of the target is changed to parallel light incident into AOTF for subsequent spectral correction. Target light at different positions enters the optical system and AOTF with different incidence angles, and the imaging positions on CCD are also different. Since the central wavelength of the AOTF diffracted light is related to the incidence angle, the relationship between them can be determined by fitting, which further identifies the relationship between the central wavelength and the CCD pixel. The spectral correction method is analyzed in detail. The experimental results show that the error of corrected spectral value is reduced by an order of magnitude compared with that of the common AOTF spectral imaging system. The spectral imaging results are clear and the accuracy of the spectropolarimetric imaging measurement system is improved.