Objective To explore the clinical effect of recombinant bovine basic fibroblast growth factor (rb-bFGF) in the adjuvant treatment of patients with depressed acne scar. Methods A total of 86 patients with depressed acne scar admitted to Women & Children's Health Care Hospital of Linyi from January to October 2024 were selected as the research subjects, and they were divided into the control group and the observation group according to the random number table method, with 43 patients in each group. All patients received CO2 fractional laser treatment. The control group was given saline irrigation and enhanced moisturization after surgery, and the observation group was given rb-bFGF for topical application on the basis of the control group. The scar conditions, inflammatory factor indexes and symptom recovery time were compared between the two groups. Results After treatment, the scores of ECCA and VSS in the observation group were both lower than those in the control group (P <0.05). After treatment, the levels of IL-10 and TNF-α in the observation group were both lower than those in the control group (P <0.05). The duration of erythema, incrustation time and edema disappearance time in the observation group were all shorter than those in the control group (P <0.05). Conclusion The adjuvant application of rb-bFGF on the basis of CO2 fractional laser treatment for depressed acne scar can effectively promote scar repair, shorten the recovery time of symptoms, such as edema and erythema, and also relieve the local inflammatory response, with definite clinical application value.