In Francis Scott Key Fitzgerald's novel "The Great Gatsby", the pursuit of materialism and existence constitutes the core theme, and it is also an important part of the author's profound social criticism of American society in the 1920s. In the novel, materialistic culture becomes the dominant force of society through the emphasis on luxury, vanity and social status. Materialism leads to excessive pursuit of external success, ignoring internal happiness and moral values. At the same time, the pursuit of existence is reflected in the role of Jay Gatsby, who represents those individuals who are constantly striving to realize the American dream. However, the novel also reflects the illusion of the American dream and the unsatisfied pursuit of existence. Even if a person has wealth and social status, he may still feel empty and dissatisfied. Through the role's lifestyle, behavior and conflict, the author reveals the conflict between materialism and the pursuit of existence, and how this conflict affects the moral and cultural values of society. Through the description of social parties, famous cars, jewels and immoral behaviors, the novel emphasizes the problems of hypocrisy, social class division and moral degeneration. Through the story of Jay Gatsby, the author reminds people to examine their own pursuits and values, and cherish their inner happiness and real interpersonal relationships. "The Great Gatsby" is a profound work of social criticism. By discussing the conflict between materialism and the pursuit of existence, it reflects the culture and values of American society in the 1920s. This theme reminds people to reflect on the balance between external success and internal satisfaction, as well as the understanding of true happiness.