〔Abstract〕 Objective To analyze and study the clinical effect of femoral nerve block guided by ultrasound and nerve stimulator in patients undergoing total knee arthroplasty. Methods 100 patients with total knee arthroplasty treated in Kaifeng Central Hospital from March 2018 to August 2019 were selected as the research objects, and they were divided into two groups by random number table method, the control group with 50 cases and the observation group with 50 cases, The control group was given continuous femoral nerve block analgesia under the guidance of nerve stimulator, and the observation group was given femoral nerve block analgesia under the guidance of ultrasound combined with nerve stimulator. The time of first ambulation, onset time, visual analogue scale (VAS) scores at 6 h, 12h, 24h, 48h in the postoperative static state, VAS scores at 24h, 48h,72h in the postoperative exercise state, and the occurrence of adverse reactions were compared between the two groups. Results There was no significant difference in VAS scores between the two groups at 6h and 48h in static state after operation (P > 0.05); The VAS score of patients in the observation group was significantly lower than that in the control group at 12h and 24h in static state after operation and at 24h, 48h and 72h in exercise state after operation. The first activity time and onset time of the observation group were significantly shorter than those in the control group, and the incidence of adverse reactions was significantly lower than that in the control group. The differences between the two groups were statistically significant (P < 0.05). Conclusion Ultrasound combined with femoral nerve block guided by nerve stimulator has a good analgesic effect in total knee arthroplasty.