Abstract: The EH4 electromagnetic imaging system is an electromagnetic automatic acquisition and processing system that combines CSAMT and MT methodologies. This paper elucidates the principles of the EH4 electromagnetic imaging system and presents application examples and results from its utilization in groundwater surveys conducted in the Bayin River-Tata Ling River basin of the Qaidam basin. Adhering to the principle of "from known to unknown," the geophysical exploration work is structured in close conjunction with geological data to acquire comprehensive geophysical data and facilitate more accurate interpretation.