Objective To investigate the value of color Doppler ultrasonography in the examination of perforating veins of the lower extremities by comparing with X-ray antegrade venography. Methods Fifty-three patients (60 lower extremities) clinically diagnosed with varicosis of the great saphenous vein from January 2014 to March 2016 were selected for color Doppler ultrasonography and X-ray antegrade venography. The results were compared and confirmed by surgery. Results Forty-seven lower extremities were diagnosed with perforating venous valve insufficiency by color Doppler ultrasonography, while 50 lower extremities by X-ray antegrade venography. There was no significant difference between the two methods (χ2=0.800, P=0.371). A total of 78 perforating veins were detected by color Doppler ultrasonography, with 1–4 perforating veins per one lower extremity. Among them, 66 perforating veins had an internal diameter of 2–5 mm, accounting for 84.6%. Except two perforating veins with an internal diameter <2 mm, the rest showed reflux. In addition, a total of 73 perforating veins presented distance to the pelma of 10–32 mm (foot-boot), accounting for 93.6%. Fifty-two lower extremities with varicosis of the great saphenous vein underwent laser ablation of the great saphenous vein with high ligation or + devascularization of perforating veins. Compared with operation findings, color Doppler ultrasonography in diagnosis of perforating venous valve insufficiency had 37 true positives, 2 false positives, 10 true negatives and 3 false negatives, and the sensitivity was 92.5% (37/40), the specificity was 83.3% (10/12), the accuracy rate was 90.4% (47/52). Conclusions Color Doppler ultrasonography can accurately localize perforating veins, measure the internal diameter and observe the degree of reflux. It is of high sensitivity and accuracy in the diagnosis of perforating venous valve insufficiency. Moreover, it is safe, simple and economical, and suitable for preoperative and intraoperative diagnosis and localization.