A Dream of Red Mansions tells the story of a feudal aristocratic family from prosperity to decline. The love and marriage tragedy of Jia Baoyu, Lin Daiyu and Xue Baochai is the center of this story. The genius of the author lies in that he didn't show this love tragedy superficially and simply, but explored the social roots of this love tragedy from the ideological character of the characters and the relationship between people, thus fully exposing the cruelty and hypocrisy of feudalism and the decay and evil of the feudal ruling class. The theme of the work is not limited to the personal love tragedy itself, but around the central event, many complicated contradictions and struggles have been launched, depicting an extremely broad picture of social life, indicating that the whole feudal society has been riddled with holes. Deeply and sharply criticized the feudal social system, political bureaucracy, marriage system and ethical relations, sharply accused feudalism of cruelty and dehumanization, and boldly and sharply predicted the historical fate of the inevitable demise of feudal society and feudal ruling class. In China, A Dream of Red Mansions was appraised as an encyclopedia for analyzing feudal society.