In order to acquire space, spectrum, and polarization information, the optical system which is applied to acousto-optic tunable filter(AOTF) imaging spectrometer is designed. The work principle of AOTF is described, then on the basis of instrument and system considerations, the optical parameters of the telescope and collimating optics are distributed reasonably. The optical design software CODE-V is used for the design, optimization and analysis of the optical system, and a refractive grating halfway along the crystal is used to simulate the effects of the AOTF. The +1 and -1 orthogonally polarized orders are produced by the AOTF at the same time. The whole system is achromatized from 400～900 nm using only three types of glass and imaging resolution excelled 32 lp/mm when the modulation transfer function (MTF) reaches 0.75.