Abstract: Based on gas-solid coupling theory, we established gas-solid coupling seepage mechanics model and numerical model for surface well pre-drainage gas, and analyzed the effect of in-situ stress and gas pressure on surface well gas drainage. The calculation results show that in-situ stress presents nonlinear negative relationship with gas production rate; output rate of gas extraction from the early stage becomes smaller with the increasing of stress significantly, and the control of in-situ stress on gas output rate is gradually weakened with the advancing of extracting; reservoir pressure is positively related to gas output rate, and the larger of coal seam gas pressure, the greater of the initial gas extraction efficiency, the higher of extraction yield, and the gas pressure will decrease with the increase of the drainage time, and the gas drainage rate decreases rapidly; the gas production rate is controlled by coal seam permeability and coal reservoir gas pressure gradient, and the former has dominant control on gas production rate at early extraction stage, and the controlling of former is less than that of latter with the advancing of extracting.