Abstract: In the process of mining, coal seam will be often affected by the flood. The physical and chemical interactions between water and coal result in the weakening of coal, which affects the stress distribution and stability of surrounding rock of face. In order to study the influence of moisture content on stress distribution at mining face, the physical and mechanical parameters under different water content (3%, 6%, 9%) in coal were firstly determined, and then theoretical analysis and numerical simulation were used to analyze the stability of coal seams in different moisture content while the face was promoted to a certain distance in the trend. The results show that: after the working face advanced the same distance, as moisture content of the coal seam increases, the coal pillar stress concentration coefficient will decrease, the peak stress will transfer to be far from the coal wall, and the damage area of the gob roof will grow larger. At the same time, the increase of water content has relative little effect on the floor deformation.