The invention relates to a gas distribution device which comprises a main board (1), lateral wings (2), a jet pipe ash-exhausting pipe (5), a baffle (6), a gas inlet pipe gas chamber, a cylinder (11) and a flange (12). A gas distribution board is formed by the main board (1) and the lateral wings (2), and the main board (1) forming an angle of 25 degrees to 60 degrees with the horizontal direction is obliquely arranged in the cylinder (11) and is connected with the wall surface of the cylinder (11); vertical upward small holes (13) are respectively arranged on the main board (1) and the lateral wings (2), and the ash-exhausting pipe (5) is communicated with an ash-exhausting hole on the main board (1); two jet pipes (3) and (4) are arranged in the cylinder (11), and the centers are respectively arranged on two equipartition points which uniformly divide the diameter of the cylinder (11) after the diameter of the ash-exhausting pipe (5) is removed; one end of the jet pipe (3) and one end of the jet pipe (4) are communicated with the main board (1), and the baffle (6) which is arranged on a midline in the cylinder (11) divides the gas chamber into two gas chambers (9) and (10) which are communicated with two gas inlet pipes (7) and (8). The invention has the advantages of easy operation, high gasification efficiency and wide material range of application.