Objective To analyze the value of color Doppler ultrasound in evaluating complications of internal arteriovenous fistula in patients undergoing long-term dialysis. Methods 64 patients who underwent long-term dialysis in the hospital from February 2015 to March 2016 were selected as the subjects. The orificium fistulae of internal arteriovenous fistula, anatomical structures of cephalic vein and radial artery and hemodynamics were detected with color Doppler ultrasound. Results The ultrasonic detection showed that among 64 patients undergoing long-term dialysis, there were 48 cases with relatively unobstructed internal arteriovenous fistula, 6 cases with thrombosis, 5 cases with stenosis, 3 cases with false aneurysm, 1 case with steal syndrome and 1 case with heart failure. The blood flow volume of orificium fistulae, the inner diameters of cephalic vein, anastomotic stoma and radial artery in patients with vascular stenosis were significantly less / shorter than those in normal subjects (P<0.05), and the blood flow volume could reach 250ml/min. Conclusion Color Doppler ultrasound can effectively detect the specific condition of vascular pathway of internal arteriovenous fistula in patients undergoing long-term dialysis. It also can accurately diagnose complications of different internal arteriovenous fistulas and find out the reasons of low blood flow, which provides important references for the clinical treatment of patients.