Objective To study the ketone luo acid tromethamine analgesia in patients with knee osteoarthritis joint replacement in advance of inflammatory factor and the influence of stress state. Methods Choice for knee osteoarthritis knee joint replacement patients 61 cases, were randomly divided into control group (30 caese) and the observation group (31caese), the control group only received intravenous anesthesia compound epidural block, on the basis of the observation group receied ketone luo acid tromethamine analgesia in advance, the contrast analysis of two groups of patients with preoperative and postoperative VAS score, cytokines and cortisol levels. Results The observation group of patients with postoperative pain VAS score (24 h, 48 h, 72 h) were significantly lower than control group (P<0.05);Observation group with 24h after IL - 8, TNF alpha level significantly lower than the control group (P<0.05), the observation group after 48h of IL-6, IL-8, TNF-a levels were significantly lower than control group (P<0.05).0bservation group 24h after surgery in patients with Cor significantly lower than the control level (P<0.05), after 48 h Cor and ACTH level observation group were significantly lower than the control group (P<0.05).Conclusion Ketone luo acid tromethamine analgesia in advance can obviously relieve knee osteoarthritis pain after joint replacement, and can significantly reduce inflammatory factor levels, reduce the postoperative patients with stress state.