Objective To investigate the application of color doppler ultrasound in the benign or malignant thyroid nodules. Methods A total of 119 patients who underwent surgeries in our hospital from January to September 2018, and the related data and results of patients were retrospectively analyzed. The patients were divided into benign group (24 cases) and malignant group (95 cases) with postoperative pathology as the gold standard. The size, distribution, morphology, color Doppler ultrasonographic features and blood flow signal values of the nodules in the two groups were observed and statistically analyzed by SPSS 20.0. Results The diagnostic accuracy of color Doppler ultrasonography was 81.05%. There were significant differences between benign and malignant nodules in size, location and number of nodules, echo, margin, calcification, strong echo, encapsulation invasion and blood flow signal value (P < 0.05). Conclusions Color Doppler flow imaging has good diagnostic value for benign and malignant thyroid nodules.