Abstract: Wound healing is a complex and highly regulated process to maintaining the skin barrier function. Wounds of diabetic patients are hard or even not healing. Non-healing diabetic foot ulcers can lead to lower-extremity amputations. Diabetic wound healing problem is the main complication that leads to high disability rate of diabetes and can threaten the lives in severe cases. The healing of skin wounds requires the synergy of multiple factors to restore the injured skin to its barrier function. The mechanisms that cause it difficult to heal diabetic wounds are complex, including oxidative stress, chronic inflammation, decreased neovascularization, peripheral neuropathy, and imbalance of extracellular matrix accumulation and remodeling. This review classifies mechanisms of diabetic wound healing and provides a reference for its further research.