To offer the true to nature target-background images used in the simulation system for homing weapons, a visual-light optical target simulator based on the liquid crystal on silicon (LCOS) technology is established. The typical output images and measurement method and data of the optical parameter are presented. It is proved that the simulator has more appropriate luminance, higher contrast and better uniformity than other conventional ones. Compared with the cathode ray tube (CRT) technology, it avoids the flicker problem and offers steady video outputs, which can greatly improve the seeker's ability of capturing the goal. So the LCOS technology is an ideal choice for optical simulators. Besides, the calculation method of illumination system based on the double fly eye lens is provided and simple results are gained which can also be used in other illumination systems of projection.