Abstract: In order to clear the suppression ability of optical system to stray light, we designed the optical system with a improved double gauss structure, whose spectrum was 0.75 m ~1 m, focal length was 12.002 mm, F was 1.8, field of view (FOV) was 1515. We obtained a optical system whose spot of every FOV was in the airy，max shift was 4.9m, spherical aberration was about 1 m，max transverse aberration was 3 m, modulation transfer function (MTF) was closed to the diffraction limity. Furthermore ,we carried on the evaluation and suppression of stray light, got the point source transmittance (PST) of stray light. Compared with the optical system without lens hood, the value of PST decreases by 76.6%~87.5% after adding the lens hood.