Abstract: The drainage effect of the roof water before mining on the working face determines the layout of the mine's drainage system, which affects the safety of mine water prevention and control. Selecting the typical working face of coal seam 2⁻² in Caojiatan coal mine in Yushen mining area, northern Shaanxi as the research object, the hydrogeological exploration of the mine and the geophysical exploration results of the apparent resistivity of the working face were comprehensively analyzed. The Jurassic Zhiluo formation aquifer and the top weathered bedrock were determined as the target layers for drainage, and the concentrated water rich section was selected as the target area for drainage, nine long-horizontal drainage boreholes were optimized and designed. Based on the principle of finite element differential solution, Comsol Multiphysics was selected to construct a single near horizontal borehole drainage concept, mathematical and numerical model. The model calibration was carried out using the monitoring data of the water head pressure during the drainage process of typical boreholes on the roof. The results show that the fitting error between the simulated and observed values of the water head pressure at the orifice during the single borehole drainage process is about 6.80%, indicating that the numerical model with calibration has a good simulation effect. The identified model was used to simulate the flow field evolution and water inflow during the drilling and drainage process, revealing a significant negative correlation between typical drilling water inflow and drilling hole pressure during the drainage process; multiple numerical calculation model for simultaneous water discharge in multiple sets of near horizontal boreholes was constructed, and six residual water head conditions of the roof aquifer were set up to simulate and predict the water inflow during the mining period of the working face. A practical linear relationship between the residual water head of the roof and accumulated drainage efficiency of the working face was established, providing support for the optimization design of drainage project in the roof of 2⁻² coal seam in the research coal mine. The research results have a certain promoting effect on the prevention and control of roof water hazard of coal mining faces and the advancement of in-situ protection technology for groundwater resources in coal mining areas.