The invention provides a coal and gas outburst simulation device. The coal and gas outburst simulation device comprises an outer shell body and an inner shell body arranged inside the outer shell bodyin a sleeved mode, wherein the outer shell body comprises a box body, an end cover is arranged above the box body, the box body comprises a bottom wall and four side walls arranged on the edge of thebottom wall, the bottom wall and the side walls are integrally formed; a sealing element is also arranged between the end cover and the box body; the inner shell body is a flexible shell; at least one loading plate is arranged between the outer shell and the inner shell, the loading plate is connected with a hydraulic loading device. According to the coal and gas outburst simulation device provided by the invention, the outer shell of the simulation device is designed as the integral box body and the end cover, the sealing element is arranged between the box body and the end cover, and the box body and the end cover are connected and fixed by a fastener, leakage of internal gas is avoided, and test results are more accurate.