Objective To observe the application effect of hyaluronic acid filling combined with botulinum toxin injection in external contour reshaping. Methods A total of 79 patients undergoing external contour reshaping admitted to our hospital from September 2023 to May 2024 were selected as the research subjects. According to the random number table method, they were divided into the control group (39 patients) and the study group (40 patients). The control group was given hyaluronic acid filling, and the study group was given hyaluronic acid filling combined with botulinum toxin injection. The clinical efficacy, facial contour parameters and aesthetic effect satisfaction were compared between the two groups. Results The total effective rate of treatment in the study group (95.00%) was higher than that in the control group (76.92%) (P <0.05). The lower facial length and lower facial width in the study group after treatment were lower than those in the control group (P <0.05). The GAIS score in the study group after treatment was higher than that in the control group (P <0.05). Conclusion In the external contour reshaping, the effect of hyaluronic acid filling combined with botulinum toxin injection is definite, which is helpful to adjust facial contour parameters and improve patients' satisfaction with aesthetic effects.