The invention discloses a method suitable for automatically cutting paper, comprising: S1, sleeving a fixing shaft of a wall-mounted paper holder with a first paper roller and a second paper roll, wherein the first paper roll and the second paper roll mutually and alternately drive the fixing shaft to rotate in clockwise and anticlockwise directions, and the rotation drives a gear to rotate in sync; S2, allowing gear-rack meshing structure to convert rotational motion in two directions on the fixing shaft into linear reciprocating motion of a same rack; S3, during unidirectional motion of thelinear reciprocating motion of the rack, allowing the rack to drive a cutting plate to move towards the paper roll having the paper pulled currently, and finishing single-travel cutting operation until a top plate in rear of the paper roll is touched; S4, during another unidirectional motion, allowing the rack to drive one cutting plate to move towards the paper roll having the paper pulled currently, and finishing another single-travel cutting operation until the top plate in rear of the paper roll is touched; S5, pulling the two paper rolls alternately, and repeating the steps S3 to S4; S6,after the paper rolls run out, disengaging the rack and the gear, and after a new paper roll is fitted in position, allowing one end of the rack, namely the start point of the rack, to re-engage withthe gear.