Under normal circumstances, wounds can be repaired successfully through their own laws. However, certain systemic diseases, such as diabetes, radiation sickness, malignant tumor, immune deficiency, malnutrition, or local pathological changes, such as local hypoxia, presence of necrotic tissue, local infection, etc. can lead to interruption of the wound repair function. Therefore, the so-called chronic trauma, also known as difficult-to-heal trauma, refers to the cessation of the trauma healing mechanism and the inability to repair the skin tissue according to the normal biological steps and rules, thus causing the trauma to remain unhealed for a long time, the infection is resistant to drugs, and the trauma deepening conventional treatment is not effective. Pan Yunchuan, Department of Burn and Skin Repair, Hainan Provincial People’s Hospital