The book "Zhuangzi" has always been divided into three chapters: "Inner, Wai, and Miscellaneous". "Tianxia" is the last article of "Zhuangzi". Although scholars have different opinions on the authors of the three articles, in general, The article can best present Zhuangzi's thoughts. The outer article may be written by Zhuangzi's posterity, while the miscellaneous article has been mixed with the theories of Taoist scholars in the Han Dynasty. Since the Republic of China, scholars have tried to analyze the creation time of this article, but there is no convincing answer. This thesis does not dare to answer this question, but try to start from the usage and usage of the word "shu" in The frequency of occurrence, try to propose a chronological upper and lower limit.