Total hip arthroplasty (THA) is a vital therapeutic tool for hip terminal disease. Frequently, hidden blood loss exists in the postoperation, which seriously affect the postoperative rehabilitation of patients. It is urgent need to solve the problem that how to fundamentally prevent and reduce hidden blood loss after THA. Although THA has its own operational reason in blood loss, and also relates to a variety of risk factors, the mechanism of hidden blood loss is not clear. Tranexamic acid has a significant role in preventing perioperative blood loss, and the correlation of hidden blood loss and fibrinolytic mechanism would be confirm necessarily in the future,which will produce positive significance in completing the mechanism of hidden blood loss.