Abstract: At present, most studies on the borehole layout parameters in the gas drainage technology of replacing roadway with borehole determine the borehole height only based on the "three-zone" distribution, while there is little research on the horizontal position and spacing of boreholes. To address this problem, taking Pingmei 15050 working face as the engineering background, the layout parameters of directional long boreholes in the roof of a large mining height working face were determined by combining physical similarity simulation experiments, theoretical analysis, and numerical simulation. Physical similarity simulation experiments were established in both the strike and dip directions of the 15050 working face. The characteristics of overburden collapse in strike and dip directions of the large mining height working face were analyzed. The height of the caving zone was found to be 11.5 m, and the height of the fracture zone was 11.5-52.0 m. The gas enrichment areas in the goaf were determined as the fracture zones near the return airway and the working face, which indicated the direction for the drilling locations of directional long boreholes. To accurately calculate the horizontal position of the corresponding boreholes, a calculation model for the horizontal position of directional long boreholes was established based on the results of physical similarity simulation in the dip direction, and a formula for calculating the horizontal position of boreholes was derived. In order to determine the reasonable spacing of boreholes, a gas drainage model for the roof directional long boreholes was established, and the gas flow direction and concentration distribution were simulated under conditions without long boreholes and with different borehole spacings. The reasonable spacing of boreholes was determined to be 5 m in the vertical direction and 3 m in the horizontal direction. Field application results showed that the average gas volume fraction was 16.1%, the average net drainage volume was 4.1 m³/min, and the average gas volume fraction in the upper corner was 0.43%, achieving the expected effect of gas control in the working face by replacing roadway with borehole.