With the large-scale exploitation of coal resources, the problem of land subsidence in the coal mining subsidence area of Huainan City was becoming more and more serious, which  brought many adverse effects to the local ecological environment, infrastructure and residents ' life, such as house cracking, road deformation and farmland flooding. And the problem seriously affected the sustainable development of the region. Therefore, it was of great practical significance to carry out subsidence monitoring in coal mining subsidence area. This paper took some coal mining subsidence areas in Gubei Coal Mine of Huainan City as the research object, and used two-stage drone aerial survey technology to obtain high-resolution digital orthophoto map (DOM), digital surface model (DSM) and digital elevation model (DEM). Combined with ArcGIS spatial analysis function, the surface subsidence information was extracted, so as to achieve the purpose of subsidence monitoring in coal mining subsidence areas. The results showed that this method could effectively and quickly identify the subsidence range and subsidence amount of coal mining subsidence area, provide reliable data support for ecological restoration and disaster warning in mining area, and also provide technical ideas and practical reference for subsidence monitoring in other similar areas.