To compare the clinical effects of enveloping flap incision and angular incision in the extraction of impacted mandibular third molars of middle position. Methods Sixty patients who underwent mandibular third molar extraction in the Department of Oral and Maxillofacial Surgery, the First Affiliated Hospital of Bengbu Medical College from January to June 2022 were randomly divided into control group and observation group, with 30 patients in each group. The control group was treated with angular incision for mandibular third molar extraction, and the observation group was treated with enveloping flap incision for mandibular third molar extraction. The operation time, bleeding degree, periodontal probing depth, pain degree, wound healing, swelling degree and mouth opening degree were compared between the two groups. Results There was no significant difference in operation time, bleeding degree and periodontal probing depth between the two groups (P >0.05). The VAS score of the observation group was lower than that of the control group at 7 days after operation (P <0.05). The Landry scores of the observation group were higher than those of the control group at 3 and 7 days after operation (P <0.05). The degree of swelling in the observation group was lower than that in the control group at 3 days after operation, and the degree of mouth opening was higher than that in the control group (P <0.05). Conclusion Compared with the angular incision, the enveloping flap incision for the extraction of impacted third molars in the middle position of the mandible is more effective in reducing pain and swelling, promoting early mouth opening and wound healing, and is conducive to promoting the recovery of patients.