Skin grafting is a common surgical method in scar repair. Generally speaking, if a large area of scar can't be stitched together or the skin at the edge of the wound can't heal, skin grafting is needed to solve the problem of wound coverage. There are many reasons for this large area skin defect, such as skin ulceration defect, skin avulsion injury, traumatic skin defect caused by large area skin tumor resection or other skin diseases, skin defect after burn scar resection, etc. If we can't cover the wound with skin tissue as soon as possible to heal it, it will affect the quality of life, even cause serious infection and systemic imbalance, and even endanger life. Therefore, skin grafting is an effective method to treat large area skin defect.