Abstract: In order to eliminate the great threat to the safety of iron mining production caused by goaf, this paper takes the goaf detection of Yuanjiacun iron mine as the research object, and studies the detection of concealed goaf by high density resistivity method.The forward models of goaf detection under simple geological conditions and complex geological conditions are established respectively.In the resistivity profile calculated by forward simulation under simple geological conditions, the goaf under different devices has the response characteristics of high resistance anomaly and sudden change of resistance.Under complex geological conditions, limestone, epidiabase and other complex geological bodies also have obvious abnormal reflection on the resistivity profile, and the dipole device has more obvious reflection on the goaf anomaly and the spatial position is more consistent.In the field goaf detection, the goaf is obviously reflected in the detection result.According to the identification mark of goaf, the abnormal distribution range of goaf is delineated.It is verified by drilling that the spatial position of resistivity anomaly is basically consistent with the actual position of goaf.Combined with the three-dimensional laser scanning of goaf, the three-dimensional model of goaf is established, and the spatial characteristic information of goaf is obtained accurately.