Objective To explore the clinical efficacy of micro-focusing ultrasound combined with botulinum toxin in lower facial rejuvenation. Methods From January 2022 to January 2023, 51 patients with lower facial rejuvenation admitted to the medical aesthetics department of our hospital were selected as the research objects, and they were randomly divided into control group (n =25) and observation group (n =26). The control group was treated with micro-focusing ultrasound, and the observation group was treated with micro-focusing ultrasound co mbined with botulinum toxin. The clinical efficacy, treatment satisfaction, facial rejuvenation index and facial sensitivity index were compared between the two groups. Results The total effective rate of treatment in the observation group was 100.00%, which was higher than 84.00% in the control group (P <0.05). The treatment satisfaction of the observation group was 96.15%, which was higher than 76.00% of the control group (P <0.05). After treatment, the modified FWS score and WSRS score of the observation group were (1.22±0.12) scores and (1.25±0.14) scoress, which were lower than (1.74±0.24) scores and (1.71±0.16) scores of the control group (P <0.05). After treatment, the pruritus score of the observation group was (0.74±0.12) scores, the 24 h burning sensation score was (0.73±0.14) scores, and the skin test score was (22.14±2.51) scores, which were lower than those of the control group (1.26±0.14) scores, (0.99±0.13) scores,(26.94±2.67) scores (P <0.05). Conclusion Micro-focusing ultrasound combined with botulinum toxin is effective in the application of lower facial rejuvenation. It can improve the clinical efficacy, optimize facial rejuvenation indicators, improve facial sensitivity, achieve higher treatment satisfaction, which is worthy of application.