A star simulator using digital adjustable light sources and a collimating optical system is presented to realize a laboratory test of celestial navigation equipment in this paper

and the technical requirements of the background light simulation are proposed as well. Based on the technical requirements of celestial navigation equipment

the overall construction of the star simulator is presented. Then

the key techniques of digital adjustable light sources

achromatic collimating optical system and adjusting for the sizes and positions of the stars are introduced

and the effect of the uniformity of background light on the star simulation is analyzed. Finally

the star simulator is fabricated and the corresponding experiments are carried out for validating its properties. Experimental results indicate that the simulator can simulate the star magnitudes of 0-5 effectively

and can offer the uniformity of background light of 94.7% and collimation better than ±2″ in the system focus of 1 647 mm and the field of view of 28'. Furthermore

the designed simulator can simulate the changes of star lights and background lights at the same time. It is concluded that the designed star simulator can satisfy the test requirements of celestial navigation in a laboratory.