The utility model discloses a pyrolysis gasification incinerator, in particular to a flashback type pyrolysis gasification incinerator, which is provided with a feeding port (1), a garbage resident chamber (2), a flue gas outlet (7) and a slag outlet (9) from the upper portion to the lower portion, wherein an incinerator inner wall (3) of the incinerator is cast with a refractory material. The flashback type pyrolysis gasification incinerator is characterized in that the bottom portion of the garbage resident chamber (2) is provided with incinerator arches (6) in space, the incinerator wall which is close to the upper portions of the incinerator arches (6) is provided with an ignition port (5), the incinerator wall on the upper portion of the ignition port (5) is provided with an air support port (4) for pyrolyzing, the flue gas outlet (7) is arranged on the incinerator wall on the lower portions of the incinerator arches (6), and the outer portion of the flue gas outlet (7) is connected with an induced draft fan. The flashback type pyrolysis gasification incinerator can be used to increase the combustion efficiency of garbage, and reduces the combustion cost.