To explore the effect of direct multi-slice computed tomography venography (MSCTV) on Cockett's syndrome.The imaging features of Cockett's syndrome diagnosed by direct MSCTV were retrospectively analyzed. The iliac vein compression tube segments were reconstructed axially. The ratio of the diameter of the lumen of pressure sections was calculated, and the boundary value was 1:3. According to the deep vein thrombosis, these data were divided into I-III types, the various therapeutic schemes were worked out, and the therapeutic effects were evaluated by the difference in diamete of lower limb before and after the treatment and 6-month follow-up.Thirty-five patients with Cockett's syndrome were diagnosed by MSCTV, 5 of which were Type I, characterized by local mild compression with the left common iliac vein, diameter ratio > 1/3, with distal vein dilation or without collateral pathway, and conservative treatment adopted. Nineteen were Type II, with significantly narrow lumen, obviously oppressed wall, diameter ratio ≤ 1/3, and intervention programmes adopted. Five out of the 19 adopted routine simple balloon dilatation, and the other 14 had stent implantation. Eleven were Type III, with obvious venous lumen stenosis or segmental occlusion, contrast agent missing in narrow department or contrast medium like a thin line through both ends of the tube, meanwhile companied with different degrees of thrombosis, and thrombolytic therapy and stent implantation were carried out. All 35 patients recovered after the treatment, 1 with recurrent thrombosis in the femoral vein after 6 months, while the others had no clear signs of recurrent thrombosis and re-stenosis. There was no pulmonary embolism.Direct MSCTV can diagnoze the Cockett's syndrome accurately and assess the compression degree of the internal iliac vein and the lesion of vascular branches.