The invention discloses an automatic yarn compensation device for a winder. The automatic yarn compensation device comprises a machine frame, a spindle position, a yarn guide compensation device and a yarn tube, wherein the spindle position, the yarn guide compensation device and the yarn tube are mounted on the machine frame from bottom to top in sequence; the yarn guide compensation device comprises a yarn guide limiting piece and a tension compensation mechanism; the yarn guide limiting piece comprises a yarn guide plate I and a yarn guide plate II which are mutually matched, each of the yarn guide plate I and the yarn guide plate II adopts a U-shaped structure which is rotated for 90 degrees, and the U-shaped opening ends of the yarn guide plate I and the yarn guide plate II are mutually opposite; the tension compensation mechanism comprises a tension disc; a plurality of pressing sheets are uniformly distributed on the inner side wall of a hollow circle; pressure input shafts with the same quantity as the pressing sheets are arranged in positions, corresponding to the pressing sheets, on the outer side wall of the hollow circle. The automatic yarn compensation device disclosed by the invention is simple in structure; the yarn guide limiting piece is additionally arranged to guide yarns to implement tension compensation; the yarn travel is tortuous and convenient to limit, so that yarn falling-off is prevented; through a compensating process cavity, the tension compensation range of the yarns is greatly improved; the cone yarn quality is high, the production cost is low, and the economic benefit is high.