Objective To explore the effect of poly-L-lactic acid (PLLA) on clinical efficacy and satisfaction of patients with facial overfilled syndrome. Methods A total of 120 patients with facial overfilled syndrome admitted to Hangzhou Starry Medical Beauty Clinic from February 2022 to February 2024 were selected as the research subjects, and they were divided into control group and observation group by the random number table method, with 60 patients in each group. The control group was treated with microfocused ultrasound, and the observation group was treated with PLLA injection. The treatment success rate, symptom improvement, adverse reactions and satisfaction were compared between the two groups. Results The treatment success rate of the observation group was 98.33%, which was higher than 80.00% of the control group (P <0.05). The incidence of skin relaxation, frozen facial expression, facial unevenness, facial ptosis or displacement in the observation group were lower than those in the control group (P<0.05). The incidence of adverse reactions in the observation group was 1.67%, which was lower than 15.00% in the control group (P<0.05). The satisfaction in the observation group was 100.00%, which was higher than 78.33% in the control group (P <0.05). Conclusion The effect of PLLA on patients with facial overfilled syndrome is accurate, which can effectively improve clinical symptoms, with lower complication incidence risk and higher patient satisfaction. It is worthy of clinical application.