The invention provides a space target characteristic measuring system, which comprises a light source sub system, a spectrograph sub system, an arc-shaped slide rail, a sample loading platform and a comprehensive control and data processing sub system, wherein the light source sub system and the spectrograph sub system are arranged on the arc-shaped slide rail; a motor is arranged in each of the light source sub system and the spectrograph sub system; the light source sub system and the spectrograph sub system can slide along the arc-shaped slide rail through the driving of the motors; the sample loading platform is positioned in the circle center position of the circular arc corresponding to the arc-shaped slide rail; a sample to be tested is fixed on the sample loading platform. The space target characteristic measuring system has the advantages that the light ray irradiation environment of outer space can be really simulated, so that the more accurate space target material characteristic parameters can be obtained; the space target characteristic study and space target imaging simulation data requirements are met.