Space-based optical monitoring system is a critical component of situational awareness. By analyzing the photoelectric imaging process of the target under the starry sky scene, the space-based space target scene imaging simulation system is designed based on surface target imaging, and a method is proposed for increasing the sampling range of secondary reflected light according to the bidirectional reflectance distribution function (BRDF) properties of the materials used on the satellite surface. Using the reflection distribution of solar panel material and polyimide film, the light concentration areas with vertex angles of 10° and 15° were determined for Monte Carlo sampling. The target imaging module includes two modes: real-time and high-quality. When the real-time imaging mode is selected, the designed system directly contacts the OpenGL pipeline for rendering and obtains an imaging frequency of over 35 Hz. When the high-quality imaging mode is enabled, the image is captured using the improved twice-sampled ray-tracing technique. The imaging effect is accurate, as is the shadow display. The imaging and monitoring of space targets are simulated by using the designed system against a background of stars, which can serve as a certain reference for the design of a space-based optical camera.