The Gumislu, co-written by Wang Dehui and Xu Yuancheng in Qing Dynasty, is a classic singing theory, but it has not been highly appraised because of its content. Rereading the book, we can find that: First of all, the book is compiled for "reading out of the book", with the conscious idea of singing as "elegant music", is a singing guide specially compiled for literati. Secondly, Gu Erlu pays the most attention to the theory of phonology and the method of articulation, and pays attention to the practical singing techniques. Thirdly, about half of the chapters of the book select and integrate the views of the previous generation of singing theory, and its reference materials almost constitute a "history of singing theory"; There are many theories of creation in the relation of voice, character and voice, singing psychology and behavior norms. Therefore, the book is systematic, theoretical and practical The "integration" of the characteristic works on the theory of singing in Kunqu shows that the theoretical framework of the traditional singing theory in the middle and late Qing Dynasty has been basically formed. Its "creativity" based on the practical experience of literati singing can be seen at least to Daoguang, Xianfeng period, Kunqu literati Qing The succession of singing is still relatively orderly. Therefore, the value of Gu Lu lies not only in the integration and creation of the singing theory of Kunqu Opera, but also in our understanding of the logical relationship between the development of singing theory from the middle of Qing Dynasty to the Republic of China.