A speech recognition device and a method thereof are adapted to recognize a Chinese word. The speech recognition device includes a lexicon model, a language model, a speech recognition module, and a parsing module. The lexicon model keeps a plurality of words. The speech recognition module performs a speech recognition processing on a voice signal conforming to a syntax structure of Chinese word description. 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. The language model based on the syntax structure of Chinese word description provides the syntax combination probability according to combination relations between the searched words. The parsing module analyzes the syntax structure of the literal word series for retrieving the Chinese word.