Objective To compare the analgesic effect of anterior approach for combined lumbar plexus and sacral plexus blocks and pericapsular nerve group (PENG) block combined with lateral femoral cutaneous nerve (LFCN) block after hip arthroplasty. Methods A total of 60 patients, aged 18‒80 years old, with American Society of Anesthesiologists (ASA) classification grades Ⅰ‒Ⅲ, who underwent elective hip arthroplasty were selected. According to the random number table method, they were divided into two groups (n=30): an anterior approach for combined lumbar plexus and sacral plexus blocks group (group A) and a pericapsular nerve group block combined with lateral femoral cutaneous nerve block group (group P). Before the induction of general anesthesia, group A was injected with 20, 10 and 20 ml of 0.33% ropivacaine under ultrasound guidance in the posterior medial iliopsoas muscle, between the internal oblique muscle and transversus abdominis muscle, and in the anterior iliopsoas muscle, respectively, while group P was injected with 20 ml and 10 ml of 0.33% ropivacaine under ultrasound guidance between the tendon of the lumbaris major muscle and pubic ramus branch as well as around the LFCN, respectively. At the end of the operation, the patients underwent self‑controlled intravenous analgesia (PCIA). Then, the Visual Analog Scale (VAS) scores and the Lovett scores of the lower limb muscle strength were recorded at rest and on movement at postoperative 2, 6, 8, 12 and 24 h were recorded. The nerve block operation time, the intraoperative dosage of propofol and remifentanil, and the postoperative dosage of sufentanil were recorded in the two groups. The number of PCIA presses, the rate of rescue analgesia use, the time to the first off‑bed activity, and the incidence of nausea and vomiting were recorded in the two groups at postoperative 24 h. Results Compared with group P, group A showed decreases in VAS scores on movement at postoperative 6 h and 8 h (all P<0.05), decreases in the Lovett scores of lower limb muscle strength at postoperative 2, 6 h and 8 h (all P<0.05), and reduced nerve block operation time (P<0.05), with a decreased number of PCIA presses at postoperative 24 h (all P<0.05). There was no statistical difference in the remaining indicators (all P>0.05). Conclusions Both anterior approach for combined lumbar plexus and sacral plexus blocks and PENG combined with LFCN block can provide effective analgesia after hip arthroplasty. Compared with PENG combined LFCN block, anterior approach for combined lumbar plexus and sacral plexus blocks can better relieve patients' pain during postoperative activities, but also has more effect on lower limb muscle strength.