Contraction scar is a scar named according to the characteristics of dysfunction it causes. It is mainly due to the scar formed by granulation, centripetal contraction of wound edge and epithelial regeneration covering in the open wound with large skin defect area. It can also be developed from an improper surgical incision or a scar formed by tearing a specific part of the skin in a specific direction after direct suture. The dysfunction and morphological changes caused by contracture scar are called scar contracture deformity, which is called scar contracture for short. The formation of contracture scar with skin defect begins with the centripetal contraction of the wound edge. Some studies believe that this process is mainly due to the differentiation of fibroblasts (or stem cells) at the base of the wound edge into muscle cells. Myoblasts are highly differentiated fibroblasts, and their cytoplasm not only contains abundant endoplasmic reticulum, but also produces collagen and many fibrils. It has the characteristics of smooth muscle cells and the same contractility. In granulation tissue, myofibroblasts account for at least 30%. In the process of wound healing, the syncytium formed by myoblasts and fibroblasts connects the wound edge skin with the wound basal tissue, and its contraction makes the wound edge drive the surrounding normal skin to contract centripetally, so the wound surface is shrinking day by day. After the wound healed, the scar tissue with a large amount of collagen fibers continued to contract, thus forming contracture scar. Contraction scar is formed after improper surgical incision or skin laceration in some specific directions, which is completely caused by the deposition and contraction of collagen fibers in scar tissue. In the process of contracture scar formation, with the centripetal contraction of the wound edge or the shortening of the straight seam wound, the peripheral skin around or at both ends of the wound is also pulled to move towards the wound or the wound center. In the trunk with wide skin, the compensation ability is strong. If the contracture trace does not exceed the limit of compensation ability, it can be adjusted gradually. Although it causes scar contracture deformity to a certain extent, it often does not cause serious dysfunction. However, in the face where organs gather and the neck of limbs where the skin is narrower than the trunk, the compensation ability is limited. Whether there is a wound with skin defect or a direct suture wound without skin defect, for example, the face is perpendicular to the eyelid margin and lip margin, or the flexion and extension side of limbs is perpendicular to the joint surface, or the surgical incision is improper, and the skin tissue in the anterior longitudinal direction of the neck is deeply lacerated, which will lead to different degrees of scar contracture deformity and its accompanying dysfunction. Especially in the limbs, if not treated in time, it can also cause a series of secondary changes, such as shortening or displacement of deep tissues such as tendons, nerves and blood vessels, deformation and dislocation of bone joints. If contracture scar occurs in childhood, it will delay treatment and cause developmental disorders. All these further aggravated the damage of morphology and function, increased the complexity of treatment, and affected the final effect of surgery. Prevention of contracture scar is better than treatment. For wounds with large skin defects, skin transplantation should be carried out in time to prevent the edge of the wound from contracting centripetally, promote wound healing and reduce the formation of scar tissue. Follow the basic principles of plastic surgery, choose a suitable surgical incision, and immediately change the vertical and vertical direction of the wound with Z-plasty. In addition, strict aseptic and non-invasive technical operation to prevent infection and reduce tissue damage is also a measure that can not be ignored to prevent scar contracture or reduce the degree of contracture.