To study the effect of triamcinolone acetonide combined with type A botulinum toxin in the treatment of patients with hypertrophic scar after burn. Methods A total of 100 patients with hypertrophic scar after burn admitted to Guizhou Provincial People's Hospital from January 2019 to January 2021 were selected as the research objects. According to the random number table method, they were divided into control group and observation group, with 50 patients in each group. The control group was treated with triamcinolone acetonide injection, and the observation group was treated with type A botulinum toxin combined with triamcinolone acetonide injection. The contents of TGF-β1 and BMP-7, scar condition, pain degree, quality of life and adverse reactions were compared between the two groups. Results The content of TGF-β1 in the scar tissue of the observation group was lower than that of the control group, and the content of BMP-7 was higher than that of the control group (P <0.05). After treatment, the VSS and VAS scores of the observation group were lower than those of the control group, and the SF-36 score was higher than that of the control group (P <0.05). The incidence of adverse reactions in the observation group was 8.00%, which was lower than 38.00% in the control group (P <0.05). Conclusion For patients with hypertrophic scar after burn, triamcinolone acetonide combined with botulinum toxin type A is effective, which can improve the degree of scar and pain, reduce the incidence of adverse reactions, and improve the quality of life.