Abstract: A system was designed in this paper, which can be used in clinical cerebral oxygen data acquisition and display, it is based on STM32 and NIRS(Near-infrared Spectroscopy). First of all, this paper introduced the basic principle of SaO₂ detection, and system scheme. Next, it illustrated the hardware system which is composed of the modules of LED, light source driver, photoelectric detection, and the signal processing. Then, the software system based on uC/OS-Ⅲ of the system was presented. At last, the feasibility and effectiveness of the system were verified by forearm occlusion and 3-D TV experiment. This system is noninvasive, small-volume, mobile-convenient, easy to use and can storage data.