To summarize the experience in the treatment of infection after limb salvage surgery for malignant tumor around knee joint, and explore the risk factor related to infection after limb salvage surgery. A clinical data of 212 patients with malignant tumor around the knee joint underwent limb salvage surgery between January 2008 and December 2017 were retrospectively analyzed. Among them, 14 cases had infection after limb salvage surgery. Two cases of acute infection were treated with sensitive antibiotics; 12 cases of chronic infection were treated with debridement and antibiotic bone cement occupying device implantation in the first stage, and prosthesis revision (8 cases), knee joint fusion (2 cases), or amputation (2 cases) in the second stage after infection control. The age, gender, preoperative chemotherapy cycle, bone marrow suppression, serum albumin, hemoglobin, operation time, postoperative drainage time, and blood transfusion volume were analyzed to screen the risk factors related to infection after