This study for a six-month trials, Randomized, open, and parallel comparison before and after its own, Stage test includes screening stage, treatment period and follow-up period. In accordance with chronic wound criteria for the patient, By producing the principle of random number, Were randomly divided into UC-MSCs Gel group or Gel group, The researchers according to the situation of wound healing time and decided to use the secondary treatment, To observe the clinical efficacy and safety.