Objective To analyze the efficacy and safety of poly-L-lactic acid filling for patients with nasolabial folds. Methods A total of 80 patients who received nasolabial fold filling treatment in Wuchang LI Sha Medical Beauty Clinic from January 2023 to January 2024 were selected as the research subjects, and they were divided into the control group and the observation group by the random number table method, with 40 patients in each group. The control group was treated with sodium hyaluronate gel filling, and the observation group was treated with poly-L-lactic acid filling. The Wrinkle Severity Rating Scale (WSRS) scores of nasolabial folds, treatment effect and adverse reaction rate were compared between the two groups. Results The WSRS scores of the observation group at 1, 3 and 6 months after injection were lower than those of the control group (P <0.05). The total effective rate of the observation group (97.50%) was higher than that of the control group (80.00%) (P <0.05). The incidence of adverse reactions in the observation group (5.00%) was lower than that in the control group (22.50%) (P <0.05). Conclusion Poly-L-lactic acid filling for patients with nasolabial folds has a definite effect. It can effectively improve nasolabial fold wrinkles, help to reduce the incidence of adverse reactions, and has good application efficacy and safety.