Abstract: Objective To compare the advantages and disadvantages of unilateral fascia iliaca block combined with light general anesthesia with laryngeal mask and subarachnoid anesthesia in patients over 65 years of age undergoing unilateral total hip arthroplasty, and to explore the individualized anesthesia scheme for elderly orthopedic patients. Methods A total of 80 patients undergoing unilateral total hip arthroplasty were divided into subarachnoid anesthesia group (Group A) and fascia iliaca block combined with laryngeal mask light general anesthesia group (Group B), 40 cases in each group. The mean arterial pressure (MAP) and heart rate (HR) before anesthesia induction (T₁), before skin incision (T₂), during modullary cavity dilatation (T₃) and out-of-door (T₄), the VAS scores and muscle strength scores of resting, active and passive activities before and after anesthesia, and the frequency of use of phenylephrine, complications and adverse reactions, the hospitalization time after operation, the quality of sleep before and 1 d after operation were recorded. The number of patient controlled analgesia (PCA) pressing within 24 h after operation was recorded. Results The postoperative VAS score and number of PCA pressing within 24 h in Group B were lower than those in group A (P＜0.05), and the analgesic effect was satisfactory. There was no significant difference in hemodynamic parameters between the two groups before and at different time points after induction of anesthesia (P＞0.05). The incidence of urinary retention in Group A was higher than that in Group B (P＜0.05), but there was no significant difference in hospitalization time and sleep quality before and 1 d after operation between the two groups (P＞0.05). Conclusions Unilateral fascia iliaca block combined with laryngeal mask light general anesthesia is safer and more effective than subarachnoid block in elderly patients undergoing unilateral total hip arthroplasty, with better postoperative analgesic effect.