Cao Xueqin's ups and downs life and the arduous process of creating "Dream of Red Mansions", and analyze the content of "Dream of Red Mansions" from the aspects of literature, history and sociology, and try to answer “who is Cao Xueqin” and %why--The Dream of Red Mansions is a masterpiece of Chinese traditional culture, and how to appreciate it - Dream of Red Mansions - these are three main issues.