Zhang Yongquan’s new book the Philology of Dunhuang Manuscripts presents a unique and profound study and provides a basic approach to understanding and researching medieval documents. As the book verifies, the author is not only versed in the evolution history of Chinese characters but also very familiar with the writing styles of Dunhuang manuscripts. He has succeeded in communicating with the original scribes and well understood their texts, and he has also done well in researching relevant documents. Therefore, all scholars specialized in Dunhuang documents must read this book to improve their research. The explanation or textual research of six colloquial words is attached at the end of this paper for reference.