Abstract: In order to efficiently search for deep hidden magnetite bodies in Kuquanshan area of Ejinagi Banner in Inner Mongolia, and evaluate the resource potential of iron polymetallic ores in this area, the authors carried out 1∶10,000 ground high-precision magnetic survey on the basis of the pre-survey. Five fractures were identified, and 2 magnetic anomalies (C1 and C2) were circled. And 2 magnetite bodies were exposed at C2 magnetic anomaly after the validation of the trench exploratory project, indicating good results in prospecting. The survey results show that the range of iron ore bodies can be better predicted by ΔT magnetic anomaly polarization operation, and the regional tectonic framework can be effectively identified by ΔT horizontal derivative operation. The contact zone+fracture+high magnetic anomaly area was preliminary established as favorable target area for iron ore mineralization in the region. The magnetite bodies after tectonic modification would result in strong negative magnetic anomalies on the surface, and this abnormal magnetization phenomenon should be paid attention to during magnetite exploration. This study could provide some experience for the exploration of skarn-type iron ore in Beishan area.