Abstract: This paper mainly analyzes and studies the safety of mining under river, First of all, through regional exploration, the water abundance, surface soil thickness, coal seam and structure are explored; Based on theoretical calculation and drilling measurement, the height of water flowing fractured zone is determined; through the analysis of aquifer and impermeable layer, the amount of precipitation and the amount of water inflow in the mine, the influence of river water on underground mining is finally determined,It has important guiding significance for mine under River Mining. At the same time, the ground subsidence is simulated by using the surface subsidence software, Providing guidance for the mine of the ground river course.