Objective To observe the effect of type A botulinum toxin masseter injection combined with hyaluronic acid chin filling in female patients undergoing maxillofacial contour reshaping. Methods A total of 70 female patients who underwent maxillofacial contour reshaping in the Department of Plastic Surgery, Hangzhou Xiaoshan District Meiyijia Medical Beauty Clinic from January to December 2024 were selected. According to the random number table method, they were divided into the control group and the observation group, with 35 patients in each group. The control group received fixed-point masseter injection of type A botulinum toxin, and the observation group received hyaluronic acid chin filling on the basis of the control group. The facial contour indicators, cosmetic effect, cosmetic satisfaction and adverse reaction rate were compared between the two groups. Results After operation, the WLF, WLF/LLF and chin angle ∠AOB in the two groups were smaller than those before operation, and the WLF and chin angle ∠AOB in the observation group were smaller than those in the control group (P <0.05). There was no significant difference in WLF/LLF between the two groups (P >0.05). There was no significant difference in LLF between the two groups (P >0.05). The total effective cosmetic rate of the observation group (94.29%) was higher than that of the control group (82.86%) (P <0.05). The cosmetic satisfaction rate of the observation group (97.14%) was higher than that of the control group (85.71%) (P <0.05). There was no significant difference in the incidence of adverse reactions between the observation group (5.71%) and the control group (8.57%) (P >0.05). Conclusion The application of type A botulinum toxin masseter injection combined with hyaluronic acid chin filling in female patients undergoing maxillofacial contour reshaping has a definite effect. It can effectively improve facial contour indicators, enhance cosmetic effect, help to improve patient satisfaction, and does not increase the incidence of adverse reactions, with good safety and effectiveness.