Abstract: ob＜x＞jective To compare the effect of ultrasound-guided pericapsular nerve group (PENG) block combined with suprainguinal fascia iliaca (SIFI) block in on postoperative pain in elderly patients undergoing total hip arthroplast (THA). Methods Fifty elderly patients scheduled for elective total hip arthroplasty w ere randomly divided into two groups, with 25 patients in each group. Group PS was given PENG block combined with SIFI block.Group F was given FIC block. Static and dynamic Visual?Analogue?Scale ( VAS ) before nerve block (T 0), 30 min after nerve block (T1), 6 h (T2), 24h (T3) and 48 h (T4) after surgery, sensory block in the mid-thigh , quadriceps motor block , cumulative fentanyl consumption after surgery, postoperative analgesia satisfaction scores and related complications were recorded . Results Static and dynamic VAS scores at T 1~T4 in group PS were lower than thoes in group F ( P <0.05). The cumulative fentanyl consumption within 24h and 24~48h after surgery in group PS were lower than thoese in group F ( P <0.00 1). Postoperative analgesia satisfaction scores in group P S was higher than that in group F ( P <0.05) . The incidence of lateral and medial sensory block of the middle thigh were higher in group PS than thoes in group F (P <0.01). The incidence of quadriceps movement block were lower in group PS than that in group F ( P <0.001). Conclusion PENG block combined with SIFI block is superior to FIC block, can provide good postoperative analgesia, reduce postoperative opioid consumption, and simultaneously reduce the incidence of quadriceps motor block, which is a clinically optional analgesic option after hip surgery.