Plugging device and method for coal mine roof cutting

The invention discloses a plugging device and method for coal mine roof cutting. The plugging device comprises a bottom plate, wherein the upper side of the bottom plate is in an arc shape, a cavity is formed in the bottom plate, two control grooves are symmetrically formed in the upper side of the bottom plate, the bottoms of the two control grooves communicate with the cavity through drainage pipes, and the drainage pipes are located in the control grooves and sleeved with connecting pipes; the connecting pipe penetrates through the control groove and is fixedly connected with the control groove, a spray head is fixedly connected to the position, located on the upper side of the bottom plate, of the connecting pipe, the position, located in the connecting pipe, of the drainage pipe is fixedly sleeved with a fixing ring, the other side of the fixing ring is fixedly connected with the connecting pipe, and a switch control device of the drainage pipe is arranged in the bottom plate; and two water leakage openi