Objective To compare the application of color Doppler ultrasound, magnetic resonance imaging (MRI) and routine detection of tumor markers in diagnosis of breast cancer. Methods The retrospective analysis was performed on the clinical data of 270 patients with breast disease undergoing Doppler ultrasound, MRI examination and routine detection of tumor markers in the hospital from March 2015 to May 2018. Taking histological pathological findings as " the golden standard", the application value in the diagnosis of breast cancer was compared. Results There were significant differences in the sensitivity, specificity, accuracy, positive predictive value and negative predictive value for the diagnosis of breast cancer by any one or any combination of color Doppler ultrasound, MRI and routine detection of tumor markers (P<0.05). In the case of single diagnosis, the sensitivity, accuracy, negative predictive value and kappa value by MRI were the highest (94.44%, 86.29%, 90.00%, 0.707). The specificity and positive predictive value by routine detection of tumor markers were the best (83.48%, 88.60%). In the case of the combination diagnosis with any two of them, the sensitivity by Doppler ultrasound and MRI was the best (94.40%). The specificity, accuracy, positive predictive value, negative predictive value and kappa value were the best by MRI and routine detection of tumor markers (91.74%, 92.59%, 94.33%, 90.09%, and 0.846). The sensitivity was the best (95.65%) by color Doppler ultrasound, MRI and routine detection of tumor markers. And the specificity and positive predictive value were lower than those by MRI and routine detection of tumor markers (89.90% and 93.33%). Conclusion Color Doppler ultrasound, MRI and routine detection of tumor markers are of certain value in clinical diagnosis of breast cancer. The clinical diagnosis should be combined with the actual situation, which can achieve better diagnostic efficiency compared with single diagnosis.