Abstract: The Jiama copper polymetallic mine, one of China's highest-altitude and largest porphyry copper mines, faces dual threats of concealed water-conducting structures and karst fissure water as mining depths exceed 4 300 m. This study optimizes the application of dynamic transient electromagnetic (TEM) detection technology for the mine and systematically develops precise detection methods for concealed water hazards. By analyzing the characteristics of concealed water hazards, forward models of typical aquifers were established, and 3 D numerical simulations were conducted to investigate induced electric field propagation and response characteristics. The dynamic TEM imaging algorithm was improved to achieve high-precision, real-time interpretation of underground TEM signals. Parameter tests involving different coil configurations, transmitting currents, stacking numbers, and detection frequencies were carried out to determine the optimal detection parameters for the Jiama copper polymetallic mine. Field tests demonstrated that the technology enabled accurate extraction of low-resistivity anomalies (apparent resistivity <6 Ω·m) within high-resistivity surrounding rock backgrounds, rapidly locating concealed water hazards. The results provide a robust geological safeguard for safe mining operations at Jiama copper polymetallic mine and open new avenues for water hazard prevention and control.