A side paper feeding device for feeding side paper to manufacture paper cups, comprising: a shuttle cam rotating in conjunction with a drive shaft and driving a shuttle plate capable of transporting the side paper located on an upper part thereof to a paper cup forming device in a horizontal reciprocating direction; a driving cam module, formed on a lower part of the shuttle cam, including a rotary cam, an oscillator cam and links arms, wherein the rotary cam formed on a rotation shaft fixedly coupled to the shuttle cam intermittently rotates a first turret, wherein the oscillator cam formed on the rotation shaft oscillates a second turret, and wherein the link arms (1360, 1370) whose respective one side ends are coupled to a first end of a first shaft of the first turret and to a first end of a second shaft of the second turret are rotatably coupled to each other at respective other side ends thereof; and a side paper transporting arm module including an arm plate, rotating arms, sub-arms and a track cam, wherein the arm plate is coupled to one end of the first turret, wherein the rotating arms are rotatably coupled at equal intervals to an outer circumferential surface of the arm plate at respective one side ends thereof, wherein the sub-arms, where suction pads for holding and releasing the side paper by vacuum are formed, are fixedly coupled to respective other side ends of the rotating arms in a direction perpendicular to the rotating arms, and wherein the track cam coupled to a second end of the first shaft of the first turret allows the sub-arms to move reciprocally, on a plane of the outer circumferential surface of the arm plate, in a section between a first point where a specific suction pad among the suction pads holds the side paper from a magazine and a second point where the side paper is released on the upper part of the shuttle plate. a shuttle cam rotating in conjunction with a drive shaft and driving a shuttle plate capable of transporting the side paper located on an upper part thereof to a paper cup forming device in a horizontal reciprocating direction; a driving cam module, formed on a lower part of the shuttle cam, including a rotary cam, an oscillator cam and links arms, wherein the rotary cam formed on a rotation shaft fixedly coupled to the shuttle cam intermittently rotates a first turret, wherein the oscillator cam formed on the rotation shaft oscillates a second turret, and wherein the link arms (1360, 1370) whose respective one side ends are coupled to a first end of a first shaft of the first turret and to a first end of a second shaft of the second turret are rotatably coupled to each other at respective other side ends thereof; and a side paper transporting arm module including an arm plate, rotating arms, sub-arms and a track cam, wherein the arm plate is coupled to one end of the first turret, wherein the rotating arms are rotatably coupled at equal intervals to an outer circumferential surface of the arm plate at respective one side ends thereof, wherein the sub-arms, where suction pads for holding and releasing the side paper by vacuum are formed, are fixedly coupled to respective other side ends of the rotating arms in a direction perpendicular to the rotating arms, and wherein the track cam coupled to a second end of the first shaft of the first turret allows the sub-arms to move reciprocally, on a plane of the outer circumferential surface of the arm plate, in a section between a first point where a specific suction pad among the suction pads holds the side paper from a magazine and a second point where the side paper is released on the upper part of the shuttle plate.