Abstract: Observing star in shortwave infrared (SWIR) spectrum has been considered as one of the important development directions of star sensor. According to the characteristic of wide waveband used in SWIR star sensor and the two feasible methods for correcting secondary spectrum in theory, an SWIR star sensor optical system with 900 nm~1 700 nm band, F number of 1.5 and the equivalent focal length (EFL) of 150 mm was designed based on the method of selecting the glass combination of the same or nearly relative dispersion coefficient and obviously different dispersion coefficient. Result shows that the secondary spectrum is corrected in broad band, the MTF in full field of view is more than 0.65 at 32 lp/mm.The system has excellent performance that can satisfy the requirement of observing star in near infrared band.