Angular glint was the main error source of the terminal guidance of surface-to-air missile seeker. In view of the problem that it was affected by directional diagram, target local illumination and so on, a method for real-time simulation of angular glint of surface-to-air missile terminal guidance based on modular idea was put forward, and the model of missile target intersection was established. The relation between the relative position of missile target and the aspect angle of radar was calculated by matrix transformation, and the angular glint of target was simulated in real time. The results showed that the line deviation of angular glint was related directly to miss distance of missile and target illuminated area. The smaller the miss distance was, the greater the line deviation was. On condition that missile was approaching target, line deviation would appear larger fluctuation due to the difference between light areas.