Objective To explore the application effect of skin soft tissue expander combined with epidermal growth factor (EGF) in scar plastic surgery. Methods A total of 48 patients who underwent scar plastic surgery in our hospital from January 2018 to December 2022 were selected as the research objects. According to the random number table method, they were divided into control group and observation group, with 24 patients in each group. The control group was treated with skin soft tissue expander, and the observation group was treated with skin soft tissue expander combined with EGF. The clinical related indexes, repair effect and adverse reactions were compared between the two groups. Results The skin expansion rate, immediate retraction rate, expansion completion time, wound healing time and type Ⅰ/Ⅲ collagen ratio of the observation group were better than those of the control group, and the differences were statistically significant (P<0.05). The total effective rate of repair in the observation group was 95.83%, which was higher than 75.00% in the control group, and the difference was statistically significant (P<0.05). The incidence of adverse reactions in the observation group was 4.17%, which was lower than 29.17% in the control group, and the difference was statistically significant (P<0.05). Conclusion The application of skin soft tissue expander combined with EGF in scar plastic surgery is effective, which can further improve the repair effect, shorten the treatment cycle and reduce the incidence of adverse reactions.