Objective To explore the application effect of polydioxanone (PPDO) line carving combined with facial hyaluronic acid filling in facial contour improvement. Methods A total of 92 patients with facial filling needs admitted to our hospital from January 2021 to September 2022 were divided into reference group and observation group by random number table method, with 46 cases in each group. The reference group was given PPDO line carving, and the study group was combined with facial hyaluronic acid filling on the basis of the reference group. The facial improvement, facial contour, satisfaction and complications were compared between the two groups. Results The excellent and good rate of the study group was 97.83%, which was higher than 82.61% of the reference group, the difference was statistically significant (P <0.05). The facial contour data of the two groups at 3 months after operation were better than those before operation, and those in the study group were better than those in the reference group, the difference was statistically significant (P <0.05). There was no significant difference in the incidence of complications between the two groups (P >0.05). The satisfaction of the study group was 95.65%, which was higher than 78.26% of the reference group, the difference was statistically significant (P <0.05). Conclusion PPDO line carving combined with facial hyaluronic acid injection is effective in patients with poor facial contouring, which can effectively improve facial aesthetics, and will not increase the probability of complications. Meanwhile, the patient satisfaction is high, which is worthy of clinical application.