1. A search-based word segmentation method for a language without a word boundary tag, comprising the steps of: a. providing at least one search engine with a segment of a text comprising at least one segment; b. searching for the segment through the at least one search engine, and returning search results each including candidate word segmentation units; and c. determining a word segmentation approach for the segment in accordance with at least part of the returned search results by performing steps of: extracting, from the at least part of the returned search results, all candidate word segmentation units appearing in the segment; scoring the extracted candidate word segmentation units; ranking subsets of extracted candidate word segmentation units in accordance with the scoring, wherein the candidate word segmentation units in each subset sequentially form the segment; and selecting a highest-ranked subset as the word segmentation approach for the segment.