1. A method, comprising: at a server having one or more processors and memory storing program modules to be executed by the one or more processors: receiving a query segmentation request including a search query, the search query further comprising an ordered sequence of Chinese characters; for each Chinese character of the ordered sequence of Chinese characters: identifying one or more predetermined search terms for the respective Chinese character, wherein each of the one or more predetermined search terms comprises one or more Chinese characters including at least the respective Chinese character, and the respective Chinese character occupies a first position in each of the one or more predetermined search terms; and in accordance with a determination that the respective one or more predetermined search terms include one or more irrelevant Chinese characters, modifying the respective one or more predetermined search terms by replacing each irrelevant Chinese character with a segmentation identifier; concatenating a subset of the modified search terms associated with the ordered sequence of Chinese characters to form a plurality of concatenated search queries based on a concatenation criterion, each concatenated search query including the ordered sequence of Chinese characters and at least one segmentation identifier that separates the Chinese characters of the ordered sequence of Chinese characters; determining a plurality of concatenated search probabilities each corresponding to one of the plurality of concatenated search queries; and in accordance with the plurality of concatenated search probabilities; identifying a specific concatenated search query corresponding to the highest concatenated search probability; segmenting the search query into two or more search terms according to one or more locations of the at least one segmentation identifier of the specific concatenated search query; identifying at least one new search term from the two or more search terms; and establishing a correlation between the identified new search term and the Chinese character occupying the first position of the identified new search term.