Abstract:A drill depth real-time measuring system based on ultrasonic ranging technology is presented, in order to enhance the intelligence and informatization of geological exploration. The main control circuit is designed with STM32F103RBT6 processor, and depth measuring circuit mainly consists of ultrasonic module. The auxiliary circuits are also built, including LED Nixie tube, LCD screen, TF-card memory circuit. At the same time, bluetooth communication circuit and GPRS communication circuit are designed to apply the Internet of Things technology in geological exploration, so that the measurements can be uploaded to the cloud server. The system improves the drilling efficiency and the controllability of the whole investigation process.