Abstract: Understanding the optical properties of space targets is crucial for monitoring space objects in orbit and ensuring the safety of spacecraft in orbit. In this paper, a mathematical simulation model of the optical properties of a satellite was proposed, including geometric and radiation models. Furthermore, a hardware-in-the-loop simulation system based on a digital micromirror device (DMD) projection unit was constructed. Model validation confirmed that the digital modeling method effectively acquires the optical properties of satellite targets. This method generated three-dimensional digital simulation images of a satellite at different spectral bands, featuring clear geometric contours. The hardware-in-the-loop (HIL) simulation system produces high-quality satellite motion scenes, meeting the needs of target detection and recognition algorithm research. The proposed method provides technical support for applications including evaluating optical camera performance and space situation awareness.