Abstract: Aiming at the problems of delay and instability of traditional communication mode in mine shaft maintenance and hoist system, a design of shaft maintenance communication device based on electromagnetic coupling technology is proposed. By installing a pair of electromagnetic coupling coils on the top of the hoist skip and under the guide wheel, the existing metal structure of the hoist wire rope, tail rope and metal pipe as the signal transmission medium pass through the coupling coil, and adopt the half-duplex communication mode based on the electromagnetic coupling communication principle to realize the two-way long-distance transmission of voice and dot control signals and ensure information synchronization and timely decision making; based on the equivalent transmission line theory, the equivalent circuit model of wire rope electromagnetic channel is established, and the channel is simplified as a closed loop with distributed inductance and resistance characteristics. The coupling mechanism and signal transmission characteristics between the coil and the closed loop are analyzed, and the parameter selection of the electromagnetic coupling coil is optimized, so that the coil is close to the resonant state within the carrier frequency range of 200-220 kHz, which improves coil coupling efficiency and energy transfer efficiency; in addition, a set of high-performance integrated circuit is designed as the core of the communication system, 32-bit microcontroller is used as the control core, and FSK (Frequency-Shift Keying) modulation and demodulation technology with strong anti-interference ability and stable signal envelope is used to realize the modulation and transmission of digital signals and the demodulation of weak signals. This device provides an economical, reliable, convenient and flexible emergency communication method. Compared with traditional communication methods, this scheme simplifies the wiring requirements, does not damage the wellbore structure, does not affect the normal operation of the lifting system, improves the emergency response ability during wellbore maintenance operations; it can achieve 70 kbit/s information transmission rate, the average bit error rate at 1 000 meters communication distance is lower than 1.6%, and the receiving end dot control signal transmission is accurate. The sound intensity of the recovered voice signal is higher than 90 dB, the audio distortion is less than 5% and the transmission delay is less than 0.2 s, which meets the requirement of mining audio equipment for distortion degree.