：Background Tranexamic acid(TXA) as antifibrinolytic inhibitor reduces bleeding has widelySused in total knee arthroplasty.The purpose of this study was to research the safety and effectiveness of the multiple doses intravenous combined topical administration Of TXA.[Methods] A total of 175 patient who underwent primary unilateral total knee arthroplasty for osteoarthritis at my inpatient department were investigated retrospectively from May 2015 to April 2019.The patients were divided into 4 groups: intra-articular injection of 1g TXA diluted in 50 ml saline after capsule closed from May 2015 to April 2016；1g of IV TXA prior to tourniquet inflation from May 2016 to April 2017；1g of IV TXA prior to tourniquet inflation,1g of IV TXA after tourniquet deflation form May 2017 to April 2018; 1g of IV TXA prior to tourniquet inflation,1g of IV TXA after tourniquet deflation,1g of IV TXA after 3 hour Of the second dose administration,1g of topical TXA at closure,from May 2018 to April 2019.Maximum hemoglobin drop,the total blood lose,hidden blood lose,blood lose to drain,transfusion rate,the incidence of deep vein thrombosis(DVT) and pulmonary embolism(PE).[Results] The Maximum hemoglobin drop,the total blood lose,hidden blood lose,blood lose to drain of Patients who received multiple doses IV and topical TXA were significantly lower than the ohter 3 groups.had fignifcantly statistically difference. Patients who received multiple doses IV and topical TXA has no transfusion occured.There was no episode of DVT and PE occured in any group after surgery.[Conclusion] The use of topical TXA and multiple of doses IV can reduce the Maximum Hb drop,the TBL,HBL,blood lose to drain without increasing the incidence of thrombosis. The use of multiple doses IV and topical TXA is safe and effctive.