Iliac vein compression syndrome (IVCS), also known as May-Thurner disease or Cockett′s syndrome, is venous reflux disorder in the lower limbs and pelvic caused by the compression of the iliac veins and presence of adhered structures in the pelvic cavity. It is not only one of the causes of venous valvular insufficiency and superficial varicose veins in the lower limbs, but also a potential risk factor for the occurrence of venous thrombosis. At present, the main modalities for its clinical examination include color Doppler ultrasound (CDFI), computed tomography venography (CTV), magnetic resonance venography (MRV), and venography, but they are limited for their inaccuracy and convenience in evaluating IVCS. Intravascular ultrasound (IVUS) serves as an ideal assessment method for IVUS with a diagnostic sensitivity of over 90% and ability to better display abnormal structures in the iliac vein and surrounding side branches and to provide real-time guidance during the operations. However, its application in this field is rarely reported in China due to its invasiveness and high price.