A class I surgical incision is a sterile surgical incision, and antimicrobial drugs can be applied prophylactically during the perioperative period, and are administered 30 minutes before the start of surgery or at the beginning of induction of anesthesia. The commonly used drugs are first-generation cephalosporins, and intravenous drugs are cefazolin and cefothiamidine, which are given intravenously before surgery. If the surgery is longer than three hours, or if blood products are administered during major surgery, an additional intraoperative dose of antimicrobial agents may be given. Prophylactic antimicrobials can also be given once more within 24 hours after surgery. It is also necessary to monitor the change of blood routine regularly after surgery and perform regular wound dressing change. Compared with the first generation cephalosporins, which have less side effects, they are mainly sensitive to Gram-staining positive cocci and have some therapeutic effect on Gram-staining negative bacilli.