Objective To study the improvement effect of red light combined with mussel-like adhesive protein hydrogel dressing on pigmentation after CO2 lattice laser treatment. Methods From March 2020 to June 2022, 97 patients with pigmentation after medical cosmetic surgery treated by CO2 lattice laser in our hospital were selected as the research objects, and they were randomly divided into study group (48 cases) and control group (49 cases). The study group was treated with mussel-like adhesive protein hydrogel dressing combined with red light. The control group was treated with red light. The clinical efficacy, onset time of pigmentation improvement, skin image score and skin barrier function index were compared between the two groups. Results The total effective rate of treatment in the study group was higher than that in the control group (P<0.05). The onset time of recovery improvement and effective improvement in the study group were shorter than those in the control group (P<0.05). The scores of skin image color after treatment in the study group were lower than those in the control group (P<0.05). The moisture and elasticity scores of skin barrier function indexes after treatment in the study group were higher than those in the control group, and the oil score was lower than that in the control group (P<0.05). Conclusion Mussel-like adhesive protein hydrogel dressing combined with red light has a definite clinical effect on pigmentation after CO2 lattice laser treatment, which can shorten the clinical improvement time, improve the skin color and skin texture, improve the skin barrier function index, and is worthy of clinical application.