Abstract: Based on the working principle of the small P13XM015-TFT-LCD star simulator and its designing, manufacturing, processing, debugging and detection technology of the whole system during the engineering application, the detection method for the two parameters of the small star simulator such as intersatellite spacing and magnitude was studied. The inter-satellite spacing was corrected by software then measured respectively and recombined to be corrected, while the adapted instrument magnitude method was used for the magnitude testing. The optical system collimating lens, preparation of simulator star database, coordinate transformation, position calculating, and system control software of the small star simulation system were designed by using modularity method. The assembly of the entire system was implemented in the laboratory, the controlling and testing platform was set up, and then the experimental results were obtained. The results show that, this system has high reliability with star database precision and position calculating error of no more than 2and angular resolution error of no more than 3.43.