Objective To analyze the impact of percutaneous endovascular stent placement in the treatment of lower limb arteriosclerosis obliterans （ASO） and its effect on ankle brachial index and adverse events. Methods A total of 68 patients with lower limb ASO from January 2021 to December 2023 were included as study subjects. All the patients were randomly divided into an observation group （percutaneous endovascular stenting, n=34） and a control group （percutaneous angioplasty, n=34） by random number table method. The differences in ankle brachial index of dorsalis pedis artery, ankle brachial index of posterior tibial artery, blood flow index of dorsalis pedis artery, vascular diameter, and incidence of treatment-related adverse events were compared between the two groups. Results （1） The ankle brachial index of dorsalis pedis artery and the ankle brachial index of posterior tibial artery in the two groups after treatment were higher than those before treatment, and the observation group presented higher index values than the control group （P<0.05）. （2） The peak blood flow velocity, blood flow, and diameter of the dorsalis pedis artery after treatment in both groups were higher than those before treatment （P<0.05）, but no difference was found between the two groups （P>0.05）. （3） There was no significant difference in the incidence of treatment-related adverse events between the two groups （P>0.05）. Conclusion Percutaneous endovascular stent placement can better improve lower extremity arterial ischaemia than percutaneous angioplasty in patients with lower limb ASO, which is beneficial for accelerating patient recovery, and the incidence of postoperative adverse events is low, ensuring treatment safety.