The invention relates to a suction-disc waste grabbing device used for machining for a specially-shaped polyurethane foam board. The grabbing device comprises a pair of transversal connection rods arranged in parallel and a plurality of longitudinal connection rods arranged on the transversal connection rods in parallel, wherein an elastic suction disc mechanism for upper-skin waste and lower-skinwaste, and an elastic suction disc mechanism for side waste are arranged on each longitudinal connection rod. Compared with the prior art, according to the suction-disc waste grabbing device used formachining for the specially-shaped polyurethane foam board, grabbing for residual waste in a machining process for the polyurethane foam board is realized in a manner of vacuum adsorption, and grabbing for upper-skin waste, lower-skin waste and side waste of the polyurethane foam board can be realized through one grabbing device, so that the working efficiency is increased, and the production cost is lowered; and the elastic suction disc assemblies capable of elastically telescoping are adopted, and have self-adaptive characteristic with regard to the uneven surfaces of foam materials, and negative-pressure partitioning control is adopted for suction discs, and suction failure caused due to gas leakage of several suction discs is prevented, so that the suction success probability is increased.