Objective To compare the differences of intraoperative blood loss, postoperative functional evaluation, local recurrence and postoperative complications between curettage and inactivation with internal fixation and bone tumor resection with reconstruction in the treatment of giant cell tumor of bone (GCTB) around the knee joint.Methods The clinical data of 42 patients with Campanacci grade III GCTB around the knee joint treated in our hospital from June 2011 to May 2020 were retrospectively analyzed. The operation time, intraoperative blood loss, postoperative hospital stay, postoperative walking time, MSTS and AKS scores of lower limb function and tumor recurrence were compared between the two methods. Objective to compare and analyze the effect of two surgical methods on the tumor prognosis and lower limb function recovery of patients with Campanacci grade III GCTB. Results The patients were followed up for an average of 46.7（7-110） months. The postoperative hospitalization days and postoperative walking time of the curettage and inactivation internal fixation group were lower than those of the tumor resection and reconstruction group, and had statistical significance (P＜0.05). The MSTS score and aks function score of the curettage inactivated internal fixation group were higher than those of the tumor segment resection and reconstruction group (P＜0.05). The tumor recurrence rate in the tumor resection and reconstruction group was significantly lower than that in the curettage and internal fixation group (P＜0.05).Conclusion Curettage and inactivation with internal fixation and bone tumor resection with reconstruction are effective methods for the treatment of Campanacci grade III GCTB around the knee joint. The former can preserve the knee joint function, postoperative hospital stay and early ambulation; the latter can significantly reduce the postoperative recurrence rate.