Objective To investigate the application effect of type ⅩⅦ collagen gel in freckle patients after facial photorejuvenation surgery and its influence on melanotropin level. Methods A total of 98 freckle patients admitted to our hospital from May to August 2024 were selected as the research subjects, and they were randomly divided into control group and observation group, with 49 patients in each group. Both groups were treated with photorejuvenation surgery, the control group was treated with conventional therapy after surgery, and the observation group was treated with type ⅩⅦ collagen gel after surgery. The clinical efficacy, wound recovery, serum inflammatory factors, melanotropin level and adverse reactions were compared between the two groups. Results The total effective rate of treatment in the observation group (85.71%) was higher than that in the control group (67.35%) (P <0.05). The wound pain duration and wound healing time in the observation group were shorter than those in the control group, and the freckle area was smaller than that in the control group (P <0.05). The levels of IL-4 and melanotropin in the observation group were lower than those in the control group, and the level of IFN-γ was higher than that in the control group (P <0.05). The incidence rate of adverse reactions in the observation group (4.08%) was lower than that in the control group (16.33%) (P <0.05). Conclusion The application of type ⅩⅦ collagen gel in freckle patients after photorejuvenation surgery is effective, which can effectively repair wound, shorten the pain time of wound skin, reduce the inflammatory reaction, and decrease the melanotropin level and the incidence of adverse reactions.