Abstract：Objective：To observe the clinical effect of acupuncture combined with ultrasound-guided nerve root block on the treatment of radicular lumbar and leg pain based on the theory of "seeking weizhong （BL40） point for lumbar and back problems". Methods：A total of 72 patients with radicular lumbar and leg pain admitted to Hangzhou Hospital of Traditional Chinese Medicine from January 2022 to December 2023 were selected and randomly divided into the control group （36 cases） and the study group （36 cases） via a random number table method. The control group received ultrasound-guided nerve root block，and the study group additionally received acupuncture in addition to the treatment of the control group based on the theory of "seeking weizhong point for lumbar and back problems". Pain levels，lumbar function，nerve conduction velocity，and incidence of adverse reactions were compared between the two groups. Results： At the end of treatment， the NRS score was 3.21±0.69 in the study group and 3.64±0.81 in the control group， the difference being significant between the two groups （t=2.425， P＜0.05）. Three months after treatment，the NRS score was 2.08±0.50 in the study group and 2.87±0.62 in the control group，the difference being significant between the two groups （t=5.951，P＜0.05）. At the end of treatment，the M-JOA score was 21.27±3.85 in the study group and 18.01±3.43 in the control group， the difference being significant（t=3.793， P＜0.05）. Three months after treatment，the M-JOA score was 23.74±4.02 in the study group and 20.96±3.71 in the control group，the difference being significant（t=33.049， P＜0.05）. At the end of treatment， the common peroneal nerve conduction velocity was （43.82±4.85）m/s in the study group and （40.06±4.11）m/s in the control group， the difference being significant（t=3.549， P＜0.05）. Three months after treatment， the common peroneal nerve conduction velocity was（ 46.70±5.73） m/s in the study group and（ 43.59±4.91）m/s in the control group，the difference being significan（t t= 2.473， P＜0.05）. At the end of treatment， the tibial nerve conduction velocity was （45.03±5.01） m/s in the study group and （41.95±4.28）m/s in the control group，the difference being significant （t=2.805，P＜0.05）. Three months after treatment，the tibial nerve conduction velocity was （48.96±5.83） m/s in the study group and （44.82±4.99） m/s in the control group， the difference being significant（t=3.237， P＜0.05）. The total incidence of adverse reactions was 2.8%（ 1/36） in the study group and 5.6%（ 2/36） in the control group，there being no significant difference between the two groups （P＞0.05）. Conclusion： The therapy of acupuncture combined with ultrasound-guided nerve root block based on the theory of "seeking weizhong point for lumbar and back problems" is effective in the treatment of patients with radicular lumbar and leg pain，with great safety.