Abstract: This paper used Trinity-site test,similar simulation and numerical simulation to investigate the effects of No.1₃,No.1₅ and No.2₂ as up-down protection stratum which protect No.2₁ in Henan Xinfeng coal mine according to the fact optimizing mine gas drainage system in the mine.The results showed that the multidirectional variation-gas pressure,content,coal thickness deformation,roof and floor deformation and stress concentration variation of protected seam under the whole protection stratums mining.The effect of eliminating outburst hazard is excellent under the mining of three protection stratums combined with gas drainage system of coal bottom road.