The invention provides a cotton-feeding cubing-roll device for a cover plate type carding machine, comprising a roller (12), a fiber feeding board (11), a cubing roll (13) and a cubing-roll housing plate (16), wherein the fiber feeding board (11) is arranged under the roller (12); the cubing roll (13) is arranged on one side of the roller; the cubing-roll housing plate (16) is arranged above the roller (13); a mote knife (14) and a small screen (15) are arranged under the cubing roll (13); the mote knife (14) is arranged on one side of the cubing roll (13) close to the roller (12); and a wrapping angle a of the small screen (15) is between 109 and 140 degrees. The cotton-feeding cubing-roll device for the cover plate type carding machine can effectively improve the utilization rate of fibrilia, and ensure even slivering, good quality of final yarn, and stabilize the blending ratio with cotton and other fibers.