Objective: to analyze and study the sonographic features of application of high frequency ultrasound in benign and malignant thyroid nodules and color Doppler flow signal, discusses it in the differential diagnosis of benign and malignant nodules in the role of. Methods: the study and analysis of two-dimensional ultrasonographic features of 42 cases of thyroid nodule patients. Results: the malignant nodules rich, internal and peripheral blood flow in the color Doppler ultrasound signal is strong, with the grade I or II blood flow signals. And benign nodules of the blood supply is relatively less, the signal is weak, with grade I or Ⅱ blood flow signals. Conclusion: high frequency ultrasound and color Doppler ultrasound in the differential diagnosis of benign and malignant thyroid nodules plays an important role in.