In modern industrial and mining environments, real-time monitoring systems are crucial for ensuring safety and improving efficiency. However, traditional communication methods are often affected by interference, long-distance transmission, and latency, which impact data stability and reliability. To address these issues, this paper proposes an EtherCAT-based master–slave field monitoring system designed for mine environments. The system provides a more efficient solution for real-time data transmission by implementing a mine-specific EtherCAT data transmission protocol. The slave hardware is based on the STM32F405 microcontroller, which reduces development costs and deployment difficulty. The master system software is developed using TwinCAT software to leverage the high-speed and deterministic communication advantages of EtherCAT, overcoming real-time data transmission challenges in underground environments. Experimental results show that the system significantly improves monitoring response speed and data reliability while reducing power consumption, offering an efficient solution for mine safety.