【Abstract】Objective To investigate the effect of tranexamic acid on intraoperative blood loss, postoperative coagulation function and its safety in dangerous placental cesarean section.Methods 60 patients with pernicious placenta previa from November 2017 to March 2018 were selected and divided into experimental group and control group according to simple random sampling method, with 30 cases in each group. Before operation, 3-5 ml of central venous blood was collected for Sonoclot coagulation and platelet function analyzer (SCA). The experimental group was given tranexamic acid sodium chloride injection 200 ml intravenous drip immediately after delivery, and the control group was given 200 ml intravenous drip of 0.9% sodium chloride injection at the same time. At the end of the operation, Sonoclot was measured and analyzed again. The blood loss and blood transfusion volume were observed. The patients were followed up for 24 hours to see if there were any complications.Results The coagulation rate (CR) of the experimental group was higher than that of the control group, and the platelet function (PF) of the experimental group was higher than that of the control group (P＜005). The blood loss, blood transfusion and suspended red blood cell transfusion in the experimental group were lower than those in the control group (P＜005). Conclusion Patients with placenta previa in disaster intraoperative use of tranexamic acid can improve patients perioperative blood coagulation function, decrease blood loss and suspended red blood cells infusion, and does not increase the incidence of adverse reactions such as thrombosis.