The invention discloses a heat injection drilling and sealing method of a heating coalbed, and relates to the hole sealing of underground heat injection coalbed methane exploitation. The invention solves the problems that the prior art does not have the heat insulation function, and a hole sealing pipe is not easy to be dismantled and recycled. The invention has the following steps that: 1, a flange is arranged at one end of a top metal pipe, the other end thereof is provided with external threads, and internal threads which are matched with the top metal pipe are arranged on a top plastic pipe; 2, the top metal pipe is screwed into the top plastic pipe; 3, a second metal pipe is connected with the top metal pipe, and the second metal pipe is inserted into the top metal pipe; 4, a double-layered pipe is inserted into a drilling hole, the third step is repeated, the metal pipe is connected with the plastic pipe until reaching the designed depth; 5, a baffle is installed between a tail-end metal pipe and a tail-end plastic pipe, thermal insulation material is filled between the flange and the baffle; and 6, the well-installed double-layered pipe is fully inserted into the drilling hole, cement paste is injected between the plastic pipe and the drilling hole, so the hole sealing is completed. The invention is applicable to the hole sealing of underground horizontal drilling.