The invention discloses a combined type pyrolysis and gasification furnace. The whole device comprises a horizontal furnace body, a vertical furnace body, a vapor leading device, a tar thermal cracking catalysis device and a cyclone dust removal device. The horizontal furnace body is perpendicularly communicated with the middle-lower portion of the vertical furnace body, the middle of the horizontal furnace body is communicated with the vapor leading device, and the other end of the vapor leading device is communicated with the middle-upper portion of the vertical furnace body. The lower end of the vertical furnace body is provided with a deslagging device, the interior of the upper end of the vertical furnace body is provided with the tar thermal cracking catalysis device which is communicated with the cyclone dust removal device through a combustible gas discharge pipeline. The horizontal furnace body is divided into a feeding section, a drying section and a pyrolysis and gasification section, the feeding section, the drying section and the pyrolysis and gasification section are combined into an inner-layer furnace body, the drying section and the pyrolysis and gasification section are combined into an outer-layer furnace body, the inner-layer furnace body stretches into the vertical furnace body, the outer-layer furnace body is connected with the barrel wall of the vertical furnace body, and the inner-layer furnace body and the outer-layer furnace body form an annular cavity. The combined type pyrolysis and gasification furnace is simple in structure, reasonable in design, high in continuous working capacity and high in pyrolysis and gasification efficiency.