Objective To study the value of the high frequency color Doppler ultrasound in the diagnosis of breast tiny cancer. Method 42 patients with breast lesions ≤1 cm which were confirmed breast cancer pathologically (the tiny cancer group) were recruited. The sonographic features were analyzed. 40 patients with breast lesions ≤1 cm which were confirmed benign lesions pathologically at the same period were recruited as the control group. Microcalcifications, blood flow and resistance index (RI) in the two groups were compared. Results There were statistically significant differences in microcalcifications, blood flow and resistance index (RI) between the two groups (P<0.05). The sensitivity, specificity, Youden index and the diagnostic conformity rates of the ultrasonic diagnosis of breast tiny cancer were 78.57%(33/42),92.50%(37/40),71.07%,and 85.37%(70/82), respectively. Conclusions The high frequency color Doppler ultrasound is simple and non-invasive. It has important clinical value for timely diagnosis and timely treatment of breast tiny cancer.