Objective To analyze the effect of combined application of unipolar radiofrequency and poly-L-lactic acid in facial rejuvenation treatment. Methods A total of 60 patients who received facial rejuvenation treatment in our hospital from February 2021 to February 2023 were selected and divided into control group and study group according to different treatment plans, with 30 patients in each group. The control group was treated with poly-L-lactic acid microneedle introduction, and the study group was treated with poly-L-lactic acid microneedle introduction combined with unipolar radiofrequency. The clinical efficacy, skin status, pain degree, facial rejuvenation degree and skin barrier function were compared between the two groups. Results The total improvement rate of the study group was 96.67%, which was higher than 73.33% of the control group (P <0.05). After treatment, the skin dark spot score, VAS score, WSRS score, FWS score and TEWL in the study group were lower than those in the control group (P <0.05), while the skin water score, elastic score, water content and oil were higher than those in the control group (P <0.05). Conclusion In the treatment of facial rejuvenation, the introduction of poly-L-lactic acid microneedle combined with unipolar radiofrequency can not only improve the skin condition, pain degree and facial rejuvenation degree, but also improve the skin barrier function of patients.