Coal seam roof cutting device

The utility model discloses a coal seam roof cutting device, and relates to the technical field of coal mine safety production equipment. The coal seam roof cutting device comprises a high-pressure water cutting tank and a water storage sand box connected with the high-pressure water cutting tank, and is characterized in that a piston is arranged at the junction of the high-pressure water cutting tank and the water storage sand box; a heat insulating layer is arranged on the inner wall of the high-pressure cutting tank; a gas generating agent is filled in the high-pressure water cutting tank; a gas generating agent replacement bottom cover is arranged at the port of the high-pressure water cutting tank; an igniter is connected with the gas generating agent end of the gas generating agent replacement bottom cover; the igniter is connected with a control cable; the control cable is electrically connected with an external power supply; a water inlet is formed in the upper part of the water storage sand box; one