Objective: To evaluate the clinical effect of treating postoperative infected bone defect of tibial plateau with external fixation ring combined with Masquelet technique. Methods: A total of 47 patients with postoperative infected bone defect of tibial plateau fracture admitted to our hospital from 2013 to 2020 met inclusion criteria were selected.All of the patients adopt circular external fixator combined therapy with induced membrane technique in installment, Ⅰ fixed period infection wound debridement, ring, Ⅱ period for bone graft or bone removal.Each record all patients Ⅰ stage postoperative 3 months after surgery, Ⅱ white blood cell count, C - reactive protein and blood sedimentation, inflammatory indexes such as phase Ⅰ postoperative 3 months after surgery, Ⅱ period of motion and knee functional score.Results: all patients of postoperative 3 months after Ⅱ period inflammatory indexes (white blood cell count, C - reactive protein and blood sedimentation), joint mobility and knee functional score more Ⅰ surgery and improved significantly (P < 0.05), 2 patients with knee joint bone defect in the larger fusion surgery. Conclusion: By staging treatment, the annular external fixator combined with Maquelet technology has a significant effect on treating postoperative infected bone defects of tibial plateau, improving knee function score and range of motion.