The invention discloses a blanking buffer cylinder based on a damping principle. The blanking buffer cylinder comprises a buffer rod, an end cover and a damping cylinder body. The damping cylinder body is a cylinder body provided with an opening in the top and a cylindrical step hole in the center. The end cover is assembled to the upper end of the damping cylinder body. The buffer rod is an unequal-diameter cylinder rod body composed of a top telescopic segment, a middle auxiliary segment and a lower damping segment. The middle auxiliary segment and the lower damping segment extend into the step hole of the damping cylinder body and are in microclearance fit with the inner wall of the step hole. A super-high-pressure cavity is filled with oil liquid, and the middle auxiliary segment of the buffer rod is promoted to float in a large-diameter cylinder hole, namely, the large-diameter cylinder hole of the damping cylinder body step hole is divided into a lower auxiliary cavity and an upper oil cavity through the middle auxiliary segment of the buffer rod; and the auxiliary cavity is filled with oil liquid as well, a damping hole communicating the auxiliary cavity with the super-high-pressure cavity is formed in the lower damping segment, an overflow channel for communicating the auxiliary cavity with the upper oil cavity is arranged on the middle auxiliary segment, and thus the blanking buffer cylinder capable of resisting the large load impact is formed.