Objective To investigate the clinical efficacy of secondary balloon dilatation or stenting based on D-dimer (D-D) in iliac vein stenosis with thrombosis. Method A prospective study was conducted in 33 patients with iliac vein stenosis or occlusion with thrombosis in Yibin First People′s Hospital from August 2016 to August 2020. They were randomized into study group (n=18) and control group (n=15), the former received lower extremity venography with balloon dilation iliac vein (8 cm) on the 4th day after the first-stage thrombolysis if the DD did not increase much (rang<10mg/L) within three days. The latter underwent venography of the lower extremities on day 7 after the first-stage thrombolysis, and ballooning dilation of the iliac vein or stenting would be considered according to the results of the angiography. The two groups were compared in the respects of D-D, calf circumference under the knee, venous reflux time, number of stents and usage rate, days of discharge and hospitalization expenses before surgery and on the 6th day after surgery. SPSS statistics 19.0 was used for statistical analysis. Depending on date type, data comparison between two groups was performed using t test or χ² test. Result The study and control groups had no significant difference in DD before operation [(15.62±6.21) vs(14.39±7.21) mg/L, P>0.05] but significant difference on day 6 after operation showed [(28.37±7.01)vs(20.54±5.78)mg/L, P<0.05]; no significant difference in the circumference at 15 cm below the knee at discharge [(1.2±0.6) vs(1.3±0.8)cm, P＞0.05] and venous reflux time at discharge[ (2.3±1.4) vs (2.4±1.6)s, P＞0.05]; significant differences in length of hospitalization [(8.35±1.51) vs (9.41±2.36) d, P＜0.05], hospitalization expenses [(56 750.6±12 387.8) vs (65 217.2±13 585.7) yuan, P<0.05], and number of stenting [3(16.7%) vs 5(33.3%), P＜0.05]. During the treatment, there were no serious life-threatening complications such as gastrointestinal bleeding between two groups. Conclusion Monitoring iliac vein stenosis and thrombosis through the D-D level can improve the efficiency of thrombolysis, reduce the use rate of stents and the cost of surgery, and reduce the length of hospital stay when the same effect is achieved in the early stage.