In order to simulate the large-area solar irradiation in the space environment, a systematic design procedure for a new projection solar simulator is presented. Based on etendue theory, the energy transfer process of the system is analyzed. An array of four xenon lamps is used as light source. An object-space telecentric projection system is designed to realize a large area and uniform illumination. The simulation of Zemax software and the actual measurement for the system are carried out to verify the rationality. The results show that the effective irradiance surface of the solar simulator is 1000 mm×1000 mm, the irradiance can get 1263 W/m2, and the irradiance non-uniformity is less than ±4.82%. The solar simulator can provide a reliable solar radiation for the space environment test of satellites, which conquers the limitations of large size and high cost of the traditional large solar simulators.