Seven-dimensional spatial information of a target scene can be obtained with utilization of the polarization imaging spectroscopy. The polarization imaging spectroscopy is applied more and more widely due to its ability of getting rich data information. We design an optical system of multi-slit polarization imaging spectrometer based on the double Amici prism. As a light splitting element, the double Amici prism can provide parallel beam dispersion of wide field to meet the needs of the multi-slit. We optimize the optical structure of the multi-slit based on the conventional slit imaging spectrometer. The pupil of wide field in the multi-slit spectrometer structure must match with the pupil of the front telescope. The imaging system and polarization spectrometer system adopt telecentric structure to match the pupil. The total length of the system is 279 mm. The system has coaxial optical path, and its structure is very compact. We evaluate the image quality of the optical system by using modulation transfer function (MTF) and spot diagrams. The results show that the MTF at typical wavelengths in each typical field is close to the diffraction limit, and the MIF is over 0.75 at 39 lp/mm. The spot diagram at each typical wavelength is in the Airy spot, which means that the imaging is almost perfect. Three slits correspond to three different polarization states. Polarizations information, spatial information, and spectral information of the target scene can be obtained by pushing-brooming.