Abstract: A novel high-accuracy star simulator with simple structure and the function of optical feedback was designed to satisfy the practical requirements of highaccuracy test and calibration of star sensor, which was a device used for celestial navigation. LED was selected as the light source. The parallel output beam was formed by means of focusing first and then collimating. The optical feedback system of the star simulator automatically adjusted the luminous intensity of its light source to keep the output intensity stable within a quite long time when the output intensity was changing.The parallelism of output beam of the star simulator reached 8, the uniformity of its output beam achieved 80% and the stability of output intensity of the star simulator reached 89% under the continuous working condition of at least 8 hours. Because the stable output intensity reduces the influence of magnitude change of the star simulator, it is very useful for improving the accuracy of test and calibration of star sensor.