A method for stitching image for medical imaging device may include obtaining a plurality of image series. Each of the plurality of image series may include one or more scanning images. The method may also include, for each of the plurality of image series, determining a tag of the each of the plurality of image series and classifying the plurality of image series based on the tags of the plurality of image series. The method may further include determining one or more groups of image series based on the classification. Image series in a same group may have a same tag. The method may also include stitching at least one image series of at least one group of the one or more groups of image series.