Among patients with abdominal aortic aneurysm, 15% to 40% of patients have common iliac aneurysm (common iliac artery aneurysms, CIAA)[1]。 For these patients, endovascular treatment should not only isolate the common iliac artery aneurysm, but also ensure the patency of the internal iliac artery to avoid pelvic ischemia, so it has become a difficult point in endovascular treatment of abdominal aortic aneurysm combined with iliac artery aneurysm. bell-bottom technique (BBT) is an active and effective treatment for abdominal aortic aneurysm combined with common iliac artery aneurysm. From January 2011 to December 2015, the Department of Vascular Surgery of Zhongshan Hospital affiliated to Fudan University treated 103 patients with abdominal aortic aneurysm combined with common iliac artery aneurysm with BBT to preserve the internal iliac artery, and achieved good results. The summary report is as follows.