Aiming at the single star simulator can only simulate one stellar target at a time, in order to solve the problems of manually replacing the star point plate when simulating other stars, low efficiency of calibration, poor consistency of the optical axis, etc. We design a single-star simulator multi-star point automatic replacement device. First, based on the working principle of off-axis reflective single star simulator, a rotating wheel type multi-star point automatic replacement device is proposed, according to the theory and design requirements of the stellar simulator to determine the size of the star point plate micro-aperture, to design the mounting and adjustment structure of the star point plate, to adjust the consistency of the star point micro-aperture with the optical axis of the optical system, and to carry out the finite element analysis and optimisation of the star point disc with the goal of light weighting. Circularity, the sources of stray light transmission are analysed and suppression measures are summarised, and a stray light cancellation structure is designed to reduce the impact on the magnitude simulation. Finally, the design of the electronic control system to achieve the automatic switching of the star point plate and the precision analysis of the error source of the influence. The results show: the single star point tensor angle error is better than 1.2″, and the optical axis consistency of the star point position is better than 10μm, which meets the accuracy requirements of the single star tensor angle and the star point position of the single-star simulator when simulating different stellar targets, and improves the efficiency of the checking and simulation accuracy of the simulation of different stellar targets.