Abstract: In order to prevent the occurrence of water damage in coal mine, it is very important to develop the prediction of mine water inrush, especially the accurate prediction of water inflow. According to the occurrence conditions of near vertical coal seam, a hydrogeological model is established by combining theoretical analysis, numerical simulation and engineering verification, and a calculation method of dynamic water inflow in open pit conversion of near vertical coal seam under multiple water gushing sources is proposed. The results show that the continuous replenishment of loose deposits in open pit can not be ignored under the conditions of open-pit switching mining near vertical coal seam. The shallow mining recharge characteristics of "pit water filling - infiltration recharge - water filling - recharge" and the deep mining recharge characteristics of "combination of bedrock aquifer reserve release and vertical open pit water recharge" are defined. Taking the Xianfeng coal mine in Qinghai Province as an example, the dynamic calculation of mine water inflow is carried out, and the comparison with the measured results proves that the method is feasible. The research results can provide a basis for mine water control work and reasonable installation of water control and drainage facilities.