Abstract: Selecting on-site case of Jixi Chengshan coal mine as an engineering example, RFPA^2D-Flow software was used to simulate the entire process of the directional hydraulic fracturing through coal seam drilling hole. The distribution and change of stress and water pressure were analyzed, with the formation and expansion of the damage and pressure relief zones studied. The gas drainage effect and gas pressure distribution during the gas drainage were contrastively studied before/after directional hydraulic fracturing through coal seam drilling hole. The results showed that the pressure relief zone between fracturing hole and controlling hole is the main channel for gas seepage after implementing directional hydraulic fracturing, thus the gas drainage effect is improved significantly.