In order to simulate the annual solar irradiation of a satellite in orbit, thus verifying and optimizing the ability of entire satellite to stray light suppression, the paper analyzes on-orbit imaging condition of optical payload and designs a scanning xenon lamp solar simulator, which has a ten dimensional scanning system including 7-dimension scanning mirror and 2-dimension folding mirror and 1-dimension sample. The controlling formula of all the mechanisms in terms of attitude and location are deduced. Then the simulation of irradiation in space environment is completed. The results show that the solar simulator scans an area of 1 700 mm×2 700 mm with the azimuth angle from -90 ° to + 90 ° and the pitch angle from -29 ° to 42.5 °. Their angular accuracies are up to 0.2 ° and 0.1 ° separately, and the position accuracy is better than 10 mm. Thus the scanning solar simulator can be applied to the accurate simulation of year-round solar irradiation condition for some satellite in orbit.