Abstract: High-precision ground magnetic survey plays a significant role in prospective investigations of minerals, providing abundant physical field information for the work of mineral resources assessment,regional geological survey and metallogenic geological structure research. This paper first explained the nature of ΔT anomaly, and then built different models for magnetic materials such as stratum, fault, anticline and syncline. Finally, the relationship between the ΔT anomalies and magnetic substance was discussed, which laid a theoretical basis for inference and interpretation of complex geological bodies, and could better guide the correct interpretation of the magnetic data.