The invention provides a mammary gland focus positioning method and device. The mammary gland focus positioning method splits the video sequences mainly based on mammary gland ultrasonic video sequence data, so as to process the video sequences into continuous image frame sequences, thus compared with a traditional ultrasonic image, increasing more information amount, and avoiding the condition that the sample is too good due to manual selection. Besides, the mammary gland focus positioning method adopts a deep learning method to train a model, so as to realize end-to-end positioning of test set data while the breast lesion area can be automatically detected, and then information of a subject is utilized to the maximum extent, and an effective auxiliary effect is provided for diagnosis ofdoctors, and the workload of the doctors is reduced.