Aimed at solving some problems in geochemical exploration, this paper chose some mining areas to carry out thermomagnetic technique application research. With the Caijiaying Pb-Zn-Ag deposit in Hebei Province as a case study area, the authors utilized the recent advances in search for concealed deposits and in recognizing the properties of secondary anomaly. The results show that the thermomagnetic technique is an effective ore-prospecting method in coverage areas.