Shuowen is not only a classic of philology, but also a classic in the history of Chinese linguistics. The construction history of Shuowen’s canonization is also the history of its acceptance and dissemination. The Han and Wei dynasties are the preparation period for the canonization of Shuowen, from Tang Dynasty to early Song Dynasty is the establishment period, the song, Yuan and Ming Dynasties are the development period, the Qing Dynasty is the golden period, and the modern and contemporary times are the transformation period. The classic quality of Shuowen is the essential factor of its canonization. The influence of social environment, the promotion of political forces, the interpretation, research and care of readers in previous dynasties, and the development of printing are also important external factors of its canonization construction. Its classical construction path shows three characteristics: the instrumentality of Chinese character books, Confucian dependence and the academic nature of Chinese character theory.