This multicenter real-world study evaluates the efficacy and safety of a novel technique for rapid intraoperative construction of tissue-engineered skin using autologous epidermal stem cells （EpiSCs） for repairing difficult-to-heal wounds. Eligible patients are randomized to receive either: （1） the experimental intervention （rapidly constructed EpiSCs-loaded scaffold combined with split-thickness skin graft via one-step or two-step procedure）， or （2） control intervention （acellular scaffold combined with split-thickness skin graft）. The primary outcome is the complete wound healing rate at 4 weeks post-surgery. Secondary outcomes include wound recurrence, scar quality （VSS/POSAS）， functional recovery （sweat test）， mortality, amputation rate, and safety profile.