The utility model discloses a device for controlling deslagging of a fluidized bed gasification furnace. The device consists of a slag dropping tube, a slag bucket (4) and a regulating valve (3), and is characterized in that the regulating valve (3) is positioned between the slag dropping tube and the slag bucket (4), the slag dropping tube consists of a shell (1) and a fire-resistant lining (2), and at least one distribution tube (5) is arranged between the lower part of the inner side of the fire-resistant lining (2) of the slag dropping tube and the upside of the regulating valve (3). The device for controlling the deslagging of the fluidized bed gasification furnace disclosed by the utility model has the advantages of simple and reasonable structure, and easiness in processing, the deslagging of the fluidized bed gasification furnace is easy to control, and after water supply is failed and is recovered in a short time, the time required for recovering a fluidized bed to a normal production state is shortened.