In order to meet the star sensor ground calibration and testing, a set of high-precision variable star chart background star map simulator was designed, the precision angular distance between the star of this system was required better than 10". Static targets with high precision was made as the standard source core device of star map simulator, matching with a brightness controlled lighting system to fulfill star point and background simulation in the same time, designing collimating optical system that males parallel light outgoing analog star chart and background, a star map was displayed at the pupil of star sensor, to achieve background controllable and high accuracy star chart position simulation. Finally, a method to improve the accuracy of the simulation star point was brought out, star point position accuracy was measured by using theodolite matching with the brightness tested of the background by light meter test. The experiments results show that, the star map simulation accuracy of the simulator is better than 10", can achieve the background brightness adjustment 26 times, and be used for high-precision star sensor ground calibration and accuracy testing.