1. A speech recognition device, adapted to recognize a Chinese word composed of a plurality of Chinese characters, comprising: a lexicon model, keeping a plurality of words, wherein each word is composed of at least one Chinese character; a speech recognition module, performing a speech recognition processing on a voice signal that conforms to a syntax structure of a Chinese word description, wherein the speech recognition processing searches words related to the Chinese word description from the lexicon model according to a feature of the Chinese word description, and produces a literal word series in digital data form by referring a syntax combination probability; a language model, based on the syntax structure of the Chinese word description for providing the referred syntax combination probability according to the connection relations between the searched words; and a parsing module, analyzing a syntax structure of the literal word series, and retrieving the Chinese word from the literal word series.