In order to obtain the star simulator sources system of the adjustable spectrum with more color temperatures and more magnitudes and it can be calibrated automatically in a wide range of spectral bands. Embarking from the amplitude and colorimetry, This paper realize the automatic calibrating multispectral light star simulator system which the color temperature is continuous adjustable from 3 900 K to 6 500 K and the magnitudes is 1 MV adjustable in -1 MV~+6 MV with double integrating spheres in 400 nm~900 nm spectral range,The light system is based on the least squares method and the white LED are treated as the main body, a variety of different peak wavelength and narrow-band spectrum LEDs to compensate the objective spectrum.Finally,the source system and star simulator are completed and debugged in the laboratory,and the results are compared with the theoretical simulation values and standard visual magnitudes. The results show that the star simulator spectrum simulation error and magnitude error are within the range of ±10% and ±10% respectively and meet the stage star sensor needs, At the same time ,In ensuring the stability of the control circuit,magnitude error can be within the range of ±5%.