Abstract: Aiming at the widely used human-computer interaction equipment, with STM32 as the control core, a capacitive human body proximity detection system is designed and implemented, which can sense the presence of human body and be used for automatic wake-up of the system. Based on the premise that the capacitive proximity sensor is sensitive to the approaching human body, the system uses a capacitive-to-digital converter FDC1004 as a measurement device, supplemented by ambient temperature compensation and a light sensing module. It has the characteristics of simple circuits, high measurement accuracy, and strong anti-interference ability. The experimental results show that in addition to being able to sense the presence of the human body in the range of 0~30 cm, it is also possible for the system to accurately measure the human body proximity distance in the range of 0~5 cm, and display the measurements on the TFT-LCD screen. The size of the sensor is adjustable so that the system can detect and measure different distances.