The invention provides a wall paper cutting device, and relates to the technical field of building machines. The wall paper cutting device comprises a guide rail, a sliding base, a cutter assembly, and a pressure adjusting assembly, the sliding base is mounted on the guide rail and in sliding connection with the guide rail, the cutter assembly is used for cutting wall paper, the pressure adjustingassembly comprises a first sliding frame, a pressing plate and an elastic part, the first sliding frame is mounted on the sliding base, the cutter assembly is slidingly mounted on the first sliding frame, the elastic part is mounted between the pressing plate and the cutter assembly, during wall paper cutting, external force acts on the pressing plate, the pressing plate is in abut joint with thesliding base and is spaced from a target cutting face by the preset distance, the pressing plate acts on the cutter assembly through the elastic part, the cutter assembly is in abut joint with the target cutting face and enables the elastic part to be compressed, according to the all paper cutting device, the strength for wall paper cutting is constant in magnitude, the cutting efficiency and precision are improved, and the wall paper damage is prevented.