To meet the practical demand for continuous monitoring of disaster-inducing water bodies in coal mine floors, an intrinsically safe STM32-based distributed resistivity monitoring system for mining is designed. The high-density resistivity method, with advantages of high resolution, intuitive results and continuous monitoring capability, is widely used for water inrush monitoring in coal mine floors. STM32 offers abundant peripheral interfaces, and its low power consumption and high programmability align with the design requirements of intrinsically safe resistivity systems. With intrinsic safety as the core premise, the system′s host and electrode converter are developed. The host handles signal transmission and data acquisition, mainly consisting of the STM32 control chip, an H-bridge regulated transmission circuit, and an ADS1256 acquisition-transmission circuit. The electrode converter is responsible for electrode state switching, comprising the STM32 control chip and a solid-state relay array circuit. Experiments verify the system′s stability and accuracy. Results indicate that the resistivity system meets intrinsic safety standards, accurately acquires electrical information, and correctly reflects geological structures.