Objective To explore the repair effect of chest expander flap repair on patients with face and neck scar and its influence on flap survival rate. Methods A total of 60 patients with face and neck scar admitted to the Department of Burn Surgery, Affiliated Hospital of Yangzhou University from January 2021 to January 2024 were selected as the research subjects. They were divided into control group and observation group by the random number table method, with 30 patients in each group. The control group was treated with traditional flap repair, and the observation group was treated with chest expander flap repair. The flap survival rate, appearance and function scores and scar degree were compared between the two groups. Results The survival rate of flap in the observation group was 100.00%, which was higher than 86.67% in the control group (P <0.05). After treatment, the scores of appearance and function in the two groups were higher than those before treatment, and those in the observation group were higher than those in the control group (P <0.05). After treatment, the scores of pain, vascularity, itching, scar color, thickness and softness in the two groups were lower than those before treatment, and those in the observation group were lower than those in the control group (P <0.05). Conclusion Chest expander flap repair on patients with face and neck scar can effectively improve flap survival rate, and the aesthetics and functionality are better, which is worthy of clinical application.