The invention relates to the technical field of corrugated pipes, in particular to a wave plate discharging device for welding a metal corrugated pipe. The device comprises a supporting table, a fixing box, a cutting mechanism, a placing mechanism, a discharging mechanism, fixing mechanisms, a lifting mechanism and a grinding wheel; the side wall of the cutting mechanism is symmetrically providedwith the fixing mechanisms, when the metal corrugated pipe enters into the fixing box, the cutting mechanism moves downward, the fixing mechanisms squeeze the metal corrugated pipe, the fixing mechanisms are propped opened gradually, the squeezing force o the fixing mechanisms is larger and larger, the fixing mechanisms fix the metal corrugated pipe, the cutting mechanism performs cutting betweenthe two fixing mechanisms, the metal corrugated pipe is prevented from shaking during cutting, so that the cut surface of the metal corrugated pipe is level; the side wall of the cutting mechanism isprovided with the grinding wheel, the thickness of the grinding wheel is decreased progressively from the periphery of the grinding wheel to the center of the grinding wheel, when the cutting mechanisms enters into the metal corrugated pipe, the grinding wheel rotates more and more close to the metal corrugated pipe, so that the cut surface of the metal corrugated pipe is leveled.