The present invention relates to an ultrasound diagnostic device. The ultrasound diagnostic device comprises: a storage unit configured to store a plurality of consecutive image frames based on ultrasound echoes reflected from a target object； an image processing unit configured to form preview images of the image frames, wherein the preview images are stored in the storage unit in association with the corresponding image frames； and a user input unit allowing a user to input a selection instruction for selecting one of the preview images, wherein the image processing unit is further configured to read out an image frame corresponding to the selected preview image from the storage unit in response to the selection instruction.
