Background: To identify the efficacy and safety of multiple doses of intravenous tranexamic acid (IV-TXA) on perioperative blood loss in patients with rheumatoid arthritis (RA) who have undergone primary unilateral total knee arthroplasty (TKA).Methods: For this single-center, single-blind randomized controlled clinical trial, 10 male and 87 female participants aged 50–75 years, with RA who underwent unilateral primary TKA were recruited. The patients received one dose of 1g IV-TXA was 10 min before skin incision, followed by articular injection 1.5 g TXA after cavity suture during the surgery. The patients were randomly assigned (1:1) into two groups and received an additional single dose of IV-TXA (1 g) for 3 h (group A) or three doses of IV-TXA (1 g) for 3, 6, and 12 h (group B) postoperatively. Primary outcomes were total blood loss (TBL), hidden blood loss (HBL), and maximum hemoglobin (Hb) decrease. Secondary outcomes were transfusion rate and D-dimer levels. All parameters were measured postoperatively during inpatient hospital stay.Results: Between September 2019 and May 2020, 104 participants were randomized, but 7 were lost to follow-up. The mean TBL, HBL, and maximum Hb decrease in group B (506.1 ± 227.0 mL, 471.6 ± 224.0 mL, and 17.5 ± 7.7 g/L, respectively) were significantly lower than those in group A (608.8 ± 244.8 mL, P = 0.035; 574.0 ± 242.3 mL, P = 0.033; and 23.42 ± 9.2 g/L, P = 0.001, respectively). No episode of transfusion occurred. D-dimer level was lower in group B than in group A on postoperative day 1 (P < 0.001), and the incidence of thromboembolic events was similar between the two groups (P > 0.05). Conclusion: In patients with RA, three doses of postoperative IV-TXA further enabled HBL and Hb decrease without increasing the incidence of adverse events in a short period of time after TKA.Trial registration: The trial was registered in Chinese Clinical Trial Registry (ChiCTR1900025013).