Aim To investigate the clinical value of color Doppler ultrasonography (CDU) for brachiocephalic trunk tortuosity in pathway selection of transradial coronary angiography (CAG). Methods 700 patients with unstable angina pectoris undergoing CAG were randomly divided into the test group (n＝362) and the control group (n＝338). According to the CDU screening with or without brachiocephalic trunk tortuosity, the test group was divided into CDU tortuosity group and CDU non-tortuosity group. According to the CAG screening with or without brachiocephalic trunk tortuosity, the control group was divided into CAG tortuosity group and CAG non-tortuosity group. Diagnostic accuracy of CDU for brachiocephalic trunk tortuosity, incidence of brachiocephalic trunk tortuosity and its effect on CAG operation success rate, operation time and complications were analyzed. Results The incidence rates of brachiocephalic trunk tortuosity in test group and control group were 9.4%, 10.7% respectively, and the difference between the two groups was not statistically significant (P＞0.05). The sensitivity of CDU diagnosis for brachiocephalic trunk tortuosity was 94.4%, the specificity was 98.7%. Compared with CDU tortuosity group, CDU non-tortuosity group and CAG non-tortuosity group, the operation success rate was decreased and operation time was increased in CAG tortuosity group (P＜0.05). The cases of radial artery spasm were 1,9, 1, and 8 respectively in CDU tortuosity group, CDU non-tortuosity group, CAG tortuosity group and CAG non-tortuosity group. 1 case of mild aortic dissection and 12 cases of catheter knotting occured in CAG tortuosity group. Conclusion CDU may provide the important reference value for interventional physicians to select more effective CAG pathway in patients with brachiocephalic trunk tortuosity.