The invention discloses a gasifying combustion furnace with a fixed furnace body. The gasifying combustion furnace comprises a furnace body, wherein at least one interactive type pouring combustion device repeatedly pouring materials in the combustion process is arranged in the furnace body. The number of the interactive type pouring combustion devices is four, the four interactive type pouring combustion devices are sequentially distributed from top to bottom, two adjacent interactive type pouring combustion devices are staggered with each other, and the two interactive type pouring combustion devices adjacent to one interactive type pouring combustion device are opposite. Each interactive type pouring combustion device comprises square steel pipes, a grate plate and a hydraulic material pusher, the square steel pipes are horizontally arranged in the furnace body, the grate plate is arranged on the square steel pipes, and the hydraulic material pusher is arranged above the grate plate. The gasifying combustion furnace can greatly improve the gasifying combustion efficiency of wet garbage and enlarge the treatment range. At the same time, the size of the grate can be greatly reduced, and accordingly, space close to the ground, occupied by the gasifying combustion furnace with the fixed furnace body can be greatly reduced.