The invention relates to an achilles tendon stitching instrument. The achilles tendon stitching instrument comprises a first bracket, a second bracket, a tightness adjusting device, a first guide sleeve, a second guide sleeve, a first positioning tube and a second positioning tube, wherein the first bracket and the second bracket are connected through the tightness adjusting device, a first positioning hole, a first guide hole, a second positioning hole and a second guide hole are respectively formed in the inner and outer arms of the U-shaped arms of the first bracket and the second bracket, the first guide sleeve is fixed through the first positioning hole, one end of the first guide sleeve is matched with the first guide hole, and one end of the first positioning tube penetrates into the interior of the first guide sleeve; the second guide sleeve is fixed through the second positioning hole, one end of the second guide sleeve is matched with the second guide hole, one end of the second positioning tube penetrates into the interior of the second guide sleeve, and through holes matched with an achilles tendon stitching needle are formed in the first positioning tube and the second positioning tube. With the adoption of the achilles tendon stitching instrument, the operation procedures are simplified, and ideal stitching effect is guaranteed.