The direction of the development for the star tracker is to realize the small size, high-precision, large field of view, multi-parameter, and high reliability. Thus, color temperature, as the secondary gist of the attitude discrimination of the star tracker, has been added into the research. This article focused on the definition of the star associated with the color temperature, and mainly researched achieving a wide range of adjustable, stable and reliable color temperature light source. In order to achieve this goal, based on analyzing the color science, photometric and radiometric studies, we improved the method of calculating the color addition, and built the entire experiment platform based on TMS320F2812 DSC and integrating sphere. Experimental results show that: the color temperature from 2 600 K to 10 000 K continuous variation can be achieved through this method. Under the same conditions (outside ambient temperature), the stability and consistency of color temperature had been validated. Moreover, it is pointed out that the most important reasons affecting the stability of the color temperature is the ambient temperature.