In order to ensure the safe mining of No.5 coal seam in Desheng Coal Industry, by analyzing the geological and hydrogeological conditions of No.5 coal seam mining in Desheng Coal Industry, it was considered that the direct and indirect aquifers of No.5 coal seam were weak in water abundance and poor in recharge conditions, which had little impact on mine production. Through the study on the development height of roof water conducting fracture zone in No.50206 Face, it was showed that the development height of water conducting fracture zone after No.5 coal seam mining had exceeded the distance between No.5 coal seam and No.2 coal seam, and could be connected to the quaternary aquifer. Therefore, it was determined that the goaf water and surface atmospheric precipitation after No.2 coal seam mining could burst into the underground, which was the key of mine water prevention and control work. It was necessary to strengthen the control of ground fissures, reduce the inflow of atmospheric precipitation and surface water along the water conducting fracture zone into the underground, and ensure the safe production of the mine.