Introduction: To investigate the effect of tranexamic acid on the removal time of drainage tube in the first unilateral total knee arthroplasty. Hypotheses: The timing of removing the drinage system can be changed when using TXA. Methods: From June 2017 to December 2018, 182 patients (42 males and 140 females) who planned to undergo primary unilateral total knee replacement were included.Age (68.1±7.1) years (60-76 years).According to the random number table method, it was divided into four groups: 45 cases of Tranexamic acid group 1 (TXA1), 46 cases of Tranexamic acid group 2 (TXA2), 46 cases of Tranexamic acid group 3 (TXA3) and None Tranexamic acid group (NTXA).TXA1-3 group intraoperative intravenous infusion combined with local application of tranexamic acid;NTXA group was locally perfused in the joint cavity with 100ml normal saline only after surgery.Differences in drainage volume, total blood loss, invisible blood loss, degree of postoperative joint swelling, Hospital for special surgery (HSS) and visual analogue scale (VAS) of pain were compared among the four groups. Results: The postoperative drainage volume of TXA1˜3 groups was 85.5±34.3ml, 189.4±72.3ml and 215.3±93.4ml, respectively, which was less than that of the non-tranexamic acid group (351.3±113.5ml). The overall difference was statistically significant (F=11.5,P=0.005). The postoperative drainage volume of tranexamic acid 1 group was less than that of tranexamic acid 2 and 3 groups.The total postoperative blood loss was 699.0±255.7ml, 710.4±296.1ml, and 715.8±248.2ml in the tranexamic acid 1-3 groups, respectively, which was less than 1130.5±354.2ml in the non-tranexamic acid group, and the overall difference was statistically significant (F=13.1,P=0.001).On the 4th day after the operation, the knee swelling degree of the tranexamic acid 1- 3 groups was 1.25±0.07, 1.13±0.12, and 1.12±0.13, respectively, which were smaller than that of the non-tranexamic acid group (1.43±0.22), and the overall difference was statistically significant (F=8.23, P=0.015).There were 2 cases of positive bacterial culture in non-tranexamic acid group and tranexamic acid group.There were 3 cases of hematoma in the non-tranexamic acid group,and 1 case of delayed wound healing. Conclusion: The application of tranexamic acid after TKA can reduce postoperative drainage volume, latent blood loss and total blood loss.The removal of the drainage tube 18h after the operation can not only fully drain,relieve pain, promote the recovery of knee joint function, but also effectively reduce the risk of infection caused by the drainage tube.