Abstract: In order to explore the influence of moisture on the mechanical properties and gas desorption performance of similar materials in outburst coal, coal powder with a particle size of less than 0.18 mm and the range from 0.18 mm to 0.25 mm with a mass ratio of 1∶1 was used as the aggregate, cement as the binder, and moisture as the dissolution, under different conditions (molding pressure, moisture ratio) to suppress the similar materials of outburst coal. The uniaxial compressive strength and initial velocity of similar materials in outburst coal were measured by rock triaxial testing machine and gas initial velocity tester. The variation of uniaxial compressive strength and initial velocity of gas dispersion of similar materials in outburst coal under different conditions were obtained. The results show that when the moisture ratio is from 12% to 20%, the uniaxial compressive strength of similar materials in outburst coal increases first and then decreases with the increase of water content; when the moisture ratio reaches 16%, the uniaxial compressive strength reaches the maximum value of 8.99 MPa; when the moisture ratio is 20%, the molding pressure is higher, the compactness of similar materials in outburst coal is larger after molding, the moisture content of the specimen is lower after demolding, and the uniaxial compressive strength is larger, the initial velocity of gas dispersion of similar materials in outburst coal decreases with the increase of the moisture ratio.