Abstract: The 3#coal seam in Slope Anze has poor physical properties with average porosity of 1.70%~4.30% and 6.44~20.50 m3/t gas content every tons of coal. Squeezing and splitting coal seams are encountered now and then. In view of the existing situation, fracturing operation with large capacity activated water easily lead to fracture height out of control, proppant invalid support and poor fracturing effect. The critical sand-carrying capacity under different thickness of coal steam and different injection mode of fracturing were determined by analyzing the critical velocity of active water sand-carrying, and the proppant grain size and composition were selected and perforation mode also was optimized. The research results were applied in 4 wells of the field, and got better effect, among which the gas production of Well Qin17-6 was more than 1 000 m3/d, and the stable output was maintained.