Abstract: To effectively address the frequent issue of electric shock in underground coal mine frequency converter power supply systems, this paper establishes a simulation model for underground medium and low-voltage power supply systems based on the standard safety parameter of 30 mA·s.Using Matlab simulation software, the influence of key factors such as the output frequency of the frequency converter, carrier frequency, smoothing capacitor, and distributed capacitance-to-ground on electric shock current is analyzed step by step.The study reveals that an increase in the output frequency of the frequency converter and the distributed capacitance-to-ground significantly elevates the electric shock current, while variations in carrier frequency have no notable effect on it.The smoothing capacitor exerts a noticeable influence on the electric shock current when its value is small, but this effect stabilizes once the capacitor reaches a certain threshold.On this basis, a safe setting value is determined using the control variable method.Additionally, the application of solid-state circuit breaker technology for rapid power cutoff is proposed, which can effectively interrupt fault currents within a short time, thereby ensuring the safety of underground personnel.