Abstract: Due to influenced by mining largely,the stress of W₂ return air crosscut in Xiaoqing coal mine is big,the closed area and rock fissures are well developed,which form air leakage channel to rise closed temperature,CO concentration.To prevent spontaneous combustion caused by air leakage in closed area of W₂ return air crosscut,a series of fire prevention measures,such as injecting nitrogen in closed area,adding sand sections in closed area,injecting consolidation in rock,grouting in roadway and injecting white mud,etc were taken,which eliminated potential problems and the spontaneous combustion accidents.