A system for image searching, comprising: at least one storage medium including a set of instructions; and at least one processor in communication with the at least one storage medium, wherein when executing the instructions, the at least one processor is configured to direct the system to perform operations including: obtaining a target image and a plurality of images, wherein at least one similar image to the target image is to be searched from the plurality of images; determining a target feature vector of the target image and a feature vector of each of the plurality of images, each of the target feature vector and the feature vectors being an N-dimensional feature vector in an N-dimensional feature space; determining, based on the target feature vector and a preset similarity range between the at least one similar image and the target image, a search region in the N-dimensional feature space, the preset similarity range defining a required range of a similarity degree between the at least one similar image and the target image; determining, among the plurality of images, one or more candidate images based on the feature vectors of the plurality of images and the search region, the feature vector of each candidate image being within the search region; and determining, among the one or more candidate images, the at least one similar image to the target image based on the preset similarity range, the target feature vector, and the one or more feature vectors of the one or more candidate images, wherein the determining, based on the target feature vector and the preset similarity range between the at least one similar image and the target image, the search region in the N-dimensional feature space comprises: dividing the preset similarity range into a plurality of sub-ranges; and for each of the plurality of sub-ranges, determining, based on the target feature vector, a sub-search region corresponding to the sub-range in the N-dimensional feature space, and wherein the search region includes a plurality of sub-search regions corresponding to the plurality of sub-ranges. at least one storage medium including a set of instructions; and at least one processor in communication with the at least one storage medium, wherein when executing the instructions, the at least one processor is configured to direct the system to perform operations including: obtaining a target image and a plurality of images, wherein at least one similar image to the target image is to be searched from the plurality of images; determining a target feature vector of the target image and a feature vector of each of the plurality of images, each of the target feature vector and the feature vectors being an N-dimensional feature vector in an N-dimensional feature space; determining, based on the target feature vector and a preset similarity range between the at least one similar image and the target image, a search region in the N-dimensional feature space, the preset similarity range defining a required range of a similarity degree between the at least one similar image and the target image; determining, among the plurality of images, one or more candidate images based on the feature vectors of the plurality of images and the search region, the feature vector of each candidate image being within the search region; and determining, among the one or more candidate images, the at least one similar image to the target image based on the preset similarity range, the target feature vector, and the one or more feature vectors of the one or more candidate images, obtaining a target image and a plurality of images, wherein at least one similar image to the target image is to be searched from the plurality of images; determining a target feature vector of the target image and a feature vector of each of the plurality of images, each of the target feature vector and the feature vectors being an N-dimensional feature vector in an N-dimensional feature space; determining, based on the target feature vector and a preset similarity range between the at least one similar image and the target image, a search region in the N-dimensional feature space, the preset similarity range defining a required range of a similarity degree between the at least one similar image and the target image; determining, among the plurality of images, one or more candidate images based on the feature vectors of the plurality of images and the search region, the feature vector of each candidate image being within the search region; and determining, among the one or more candidate images, the at least one similar image to the target image based on the preset similarity range, the target feature vector, and the one or more feature vectors of the one or more candidate images, dividing the preset similarity range into a plurality of sub-ranges; and for each of the plurality of sub-ranges, determining, based on the target feature vector, a sub-search region corresponding to the sub-range in the N-dimensional feature space, and wherein the search region includes a plurality of sub-search regions corresponding to the plurality of sub-ranges.