Abstract: Objective To study the occurrence of complications after opening wedge high tibial osteotomy(OWHTO), analyze the risk factors and summarize the prevention and treatment measures. Methods The medical records and imaging data of 105 patients with knee osteoarthrosis who underwent OWHTO in our hospital were retrospectively analyzed. There were 88 cases in the uncomplicated group(group A) and 17 cases in the complication group(group B). The general information(age, gender, side, course of diseases, body mass index(BMI), smoking, drinking, complications, etc.), operation time, imaging measurement, blood routine indexes of two groups were statistical analyzed. Multivariate logistic regression analysis was used to study the risk factors of perioperative complications. Results The average age of all patients was(59.92±4.81) years old, including 27 males and 78 females. The total incidence of postoperative complications was 12.38%. The results of multivariate Logistic regression analysis showed that course of disease(OR=1.636, P=0.015), operation time(OR=1.064, P=0.023), BMI(OR=1.432, P=0.042) and osteotomy space(OR=4.203, P=0.003) were independent risk factors for postoperative complications of OWHTO. Conclusion Course of disease, operation time, BMI and osteotomy space are independent risk factors for postoperative complications of OWHTO. It is of great significance to control the body weight and shorten the operation time, especially to take timely preventive measures for patients with long course of disease and large osteotomy gap to reduce the occurrence of postoperative complications.