The famous mathematician Mr. Hua Luogeng said: "To read a book, the more you read, the thinner it becomes." The process of reading a book and getting thinner is the process of continuously deleting redundant information during repeated readings, condensing The main methods are: making an outline and writing a summary. The former must clarify the context of the article and then summarize the content paragraph by paragraph on the basis of careful reading; the latter must also read repeatedly to grasp the key points of the text and highly condense the content. The condensation method is a method of reading that is erudite and anti-conventional, accumulating thick books and reading thin books.