In order to satisfy the high precision calibration of the detection ability of star sensor in different spectrum distribution, a design method of star simulator light source system with spectrum adjustable based on digital micro-mirror device was presented, which could solve the issue of star sensor optical signal calibration precision caused by the mismatch between star simulator′s color temperature and star sensor′s detecting color temperature. Firstly, according to the design technical specification, the Czerny-Turner optical system was selected as the light source optical system, two main aberrations of Czerny-Turner system, coma and astigmatism, were analyzed, and a coma-corrected Czerny-Turner structure was adopted. Secondly, the initial structure parameters of Czerny-Turner optical system was calculated by MATLAB and then optimized by ZEMAX. Finally, the tolerance analysis of the optical system was carried out. The result shows that the spectral resolution is less than 2 nm within the working spectrum range from 400 nm to 1 100 nm, which meets the requirements, and effectively diminishes the calibration error caused by spectral mismatch.