The invention relates to the technical field of printing, and discloses a printing paper cutting device capable of ensuring quantitative cutting and smoothing printing paper. The printing paper cutting device capable of ensuring the quantitative cutting and smoothing the printing paper comprises a base, the base is used for supporting and stabilizing the whole device, and a second gear, a third gear, a first connecting rod and a moving block match for use, so that a moving block is used for driving a cutting knife to do reciprocating motion to quantitatively cut the paper, it is guaranteed that the size of the cut paper is consistent, the uniformity of products is guaranteed, through cooperative use of a first gear, a first sliding sleeve, a second connecting rod and a smoothing block, thepaper can be smoothened when the printing paper is cut, the flatness of the paper is guaranteed, the situation that creases exist in a cutting process and influence the cutting effect is prevented, through cooperative use of a second sliding sleeve, a first supporting rod, a second supporting rod and a clamping plate, it is guaranteed that the folded paper is kept stable through the clamping plate when the paper is cut, and therefore shaking generated in the paper cutting process is avoided, and the cutting face is more neat.