1, Thoroughly remove the epithelium of the inner wall of the pocket to prevent the epithelium from making premature contact with the tooth surface and forming a long bonded epithelium. 2, Expose the bone surface as little as possible during surgery, or shorten its exposure time, and the gingival flap should be covered with the bone surface as much as possible at the end of surgery to reduce bone resorption. Modified Widman method has this advantage. 3, root surface leveling should be thorough, and try to preserve the healthy residual fibers on the root surface near the alveolar ridge. 4, the gingival flap should be gently pressed for a moment after resetting to make it fit closely to the tooth surface and reduce the thickness of the blood clot. Liang Zhaozhong, Department of Special Oral Surgery, Urumqi Stomatological Hospital 5. Prevent infection and prevent the gingival flap from peeling or tearing from the tooth surface after surgery.