[Objective] After total knee replacement (total knee replacement, TKR), pressurize the joint cavity with physiological saline to analyze the effect of improving blood loss and joint function. [Method] Analysis of 176 patients undergoing TKR surgery in our hospital from February 2018 to December 2019, patients in the compression group received restrictive infusion (92 cases), and patients in the traditional group received free infusion (84 cases ). [Results] The total blood loss during operation, dominant blood loss and postoperative recessive blood loss in the compression group were significantly lower than those in the traditional group (P<0.05); the VAS and ODI scores in the compression group were significantly lower In the traditional group, the HSS score was significantly better than the traditional group (all P<0.05); the incidence of adverse reactions such as superficial venous thrombosis, deep venous thrombosis, fat liquefaction, and delayed healing in the pressurized group was significantly lower than that in the traditional group (P<0.05) . [Conclusion] Pressurized infusion of normal saline in the joint cavity after TKR is beneficial to reduce the amount of postoperative hidden bleeding, which in turn reduces the total blood loss during the perioperative period; pressurized infusion also helps to reduce surgical trauma and promote the process of postoperative joint function recovery, Effectively relieve subjective pain and reduce the incidence of adverse reactions.