Abstract: The display dynamics software is used to numerically simulate the punching process and explore the fracture of coal and rock under the impact of high-pressure water jets. We analyze the process and mechanism of cutting holes when the jet water column impacts coal and rock with or without confining pressure, and demonstrate the process that the coal and rock mass is subjected to tensile and shear forces to cause horizontal and vertical cracks to form and gradually extend into a crack network. The research results show that when the water jet impacts the coal and rock to form pores, it will form fissures for gas migration in the surrounding coal and rock, and the pore-forming damage range is affected by the confining pressure. When the jet parameters are constant, the confining pressure will hinder the expansion of the hole depth and pore size, but will further expand the development range of the surrounding fissures, and the expansion range will increase by about 40% under the action of the 20 MPa confining pressure.