The invention discloses a paper cutting machine. The machine comprises a rack, a paper cutting mechanism, a paper pressing mechanism and a paper pushing mechanism, wherein the paper cutting mechanismcomprises a paper cutting motor, a belt wheel transmission mechanism, a mounting frame and a cutter mechanism; the cutter mechanism comprises a cutter, a knife rest, a knife rest connecting rod a, a knife rest mounting base and a knife rest connecting rod b. When the machine operates, the paper cutting motor drives a screw rod of a ball screw to rotate, a nut of the ball screw pushes a sliding wheel to move along a sliding rail on a rail plate, and a power transmission rod is pushed by a jacking spring to move up and down, so that the cutter of the cutter mechanism is driven to cut paper up and down; a movable plate pushes a movable plate b to move to make a cam to rotate, a vertical ejector rod moves up and down under the action of a paper pressing spring and the cam, and therefore a pressing plate is driven to ascend and descend. The paper cutting machine is low in noise, capable of saving energy, environmentally friendly, complete in safety protection measure, compact in structure,low in manufacturing, small in size and convenient to transport.