In order to satisfy the high-precision technical requirements of static star simulator, according to the optical design characteristics of traditional star simulator, the paper designed a collimating objective optical system with little distortion, flat field apochromatism, made the simulated star chart by parallel light exit, on the entrance of star sensor produced star chart, and realized the static star simulator could simulate star accuracy static star simulator. This system is designed by four lenses, effective aperture is 20mm, and focal distance is 190.84mm. By imaging quality analysis it shows that in the angular field of view 6°×6°, the relative distortion of collimating objective optical system is less than 0.01%, MTF at 40lp/mm reached 0.6, and has higher imaging quality. It proves that the optical system meet the design requirements.