1, anatomical basis of the flap: the arteries of the flap come from the innominate artery of the little finger and the ulnar artery trunk and the deep palmar branch of the ulnar artery. The main trunk of the ulnar artery anastomoses with the superficial palmar branch of the radial artery to form the superficial palmar arch. On the ulnar side of the superficial metacarpal arch, the ulnar metacarpal innominate artery of the little finger emanates, and from the long axis of this artery, a cutaneous branch supplies the distal 2/3 of the flap in the small interphalangeal area. In front of or proximal to the ulnar arterial trunk and the deep palmar branch through the bean hook canal, a myocutaneous branch is issued from the short flexor of the little finger and the interval of the little finger adductor muscle to supply the short palmar muscle and the proximal 1/3 flap of the lesser interphalangeal area. The ulnar artery trunk emits about three to seven branches, the thickest of which is the small interphalangeal branch. The three sources of dermal branches are anastomosed subcutaneously to form a vascular network. The veins are all companion veins. The nerve of the flap comes from 1~2 small interfascicular branches from the superficial branch of ulnar nerve. 2, repair finger abdominal scar contracture flap selection: finger abdominal scar contracture caused by finger trauma, scald (burn) injury, if the scar is shallow, remove the scar and release the contracture left after the trauma, feasible full-thickness skin piece free graft. However, it often causes the formation of re-contracture and affects the function of the finger. If the scar is deeper, flap repair can be used. Such as distal or adjacent finger tipped flap, but it needs to be kept in uncomfortable forced position, which affects the functional exercise of the finger after surgery; and it needs to be operated again, and the repaired flap is senseless. The adjacent finger island flap is limited in size and requires sacrifice of one finger nerve if sensation is restored to the flap. The retrograde dorsal palmar artery island flap is a better method. However, Gu Yudong et al. considered the dorsum of the hand to be more cosmetically relevant. The flap designed by our group is closer to the healthy finger in terms of texture and color. 3. Advantages of the flap: (1) The flap has less effect on the destruction of hand function and aesthetic appearance. (2) The texture and color of the flap is close to that of the recipient area, and the appearance is good after repair. (3) The flap has independent artery, vein and nerve innervation, the position and caliber of blood vessels are more constant, easy to cut and take, and the flap has a high survival rate and can be made into a flap with sensation. (4) Longer vascular tips, larger transfer range, wider indications, and can be used to repair skin defects in the whole finger belly, wrist and large interphalangeal area. (5) The donor area is less damaged and can be directly sutured. Disadvantages: ligation of the ulnar artery trunk or superficial palmar arch is required, but it has little effect on the blood supply to the hand.