Abstract: In order to study the impact of dynamic development of mining subsidence area on the surface confluence ,this paper,with the Guang Fu River,Si River,and Bai Ma River Basin as the study areas and based on the upgraded method of the topographic map in mining area influenced by the subsidence,proposed the statistical tec hnical route of lowland catchment range in subsidence area,used the confluence polygon extraction method of Arc Hydro Tool Software, and analyzed the impact of mining subsidence on watershed catchment. The research results showed that the mining subsidence's influence on the surface confluence dramatically increased at the initial sta ge,but slowed down gradually and tended to be stable when surface subsidence was less violent. The location of subsidence was the main factor that affected the surface confluence instead of subsidence intensity and subsidence scope. The natural basin watershed was destroyed by mining subsidence,and the surface confluence would bec ome in disorder. The original watershed demarcation gradually disappeared,leading to a series of ecological and environmental problems. Strengthening the statistics of lo wland confluence scope in mining subsidence area,could provide the decision-making for the governance of ecological environment in mining subsidence area.