Abstract: In order to find out the location, depth and distribution range of the mined-out areas in Fushun coal mine, and comprehensively considering the factors affecting the geophysical methods in the cities, the method of high-precision gravity survey was firstly used to study the mined-out areas in the area. Firstly, by analyzing the physical differences of the mined-out areas, a theoretical model was established for forward calculation and preliminarily studied on applicability of the gravity method. Then, a large-scale work of high-precision gravity survey was arranged in the study area, and through potential field separation,3D apparent density inversion and boundary identification calculation of the Bouguer gravity anomaly, the location, depth, boundary and tectonic distribution of the mined-out areas were inferred. The research results show that the method of high-precision gravity survey combined with effective data processing method can play an important role in the detection of mined-out areas in urban coal mines.