K3 sandstone was the dividing line of Upper Shihezi formation and Lower Shihezi formation of the Permian series, the thickness of K3 sandstone was often large. Because of the uneven distribution of the K3 sandstone in Wolonghu coal mine and the deficiency understanding of K3 sandstone, water inrush accident happened twice when going through the K3 sandstone in Wolonghu coal mine in the construction of main shaft, based on the situation, the thickness of sandstone and lithologic features of the K3 sandstone in Wolonghu coal mine, and the effect?to?the?water?abundance were analyzed, which had a certain reference value for similar water disaster prevention and control work in mine.