Fortress Besieged was regarded as a classic of modern Chinese novels. The novel mainly tells the story of a character, Fang Hongjian, who lived inside and outside the besieged city. When faced with marriage, career, education and other problems, he experienced a series of thoughts and choices and finally chose to spend the rest of his life inside the besieged city. The novel used Fang Hongjian and Sun Roujia's marriage as an example to describe the drawbacks of traditional Chinese marriage and the marital situation in the besieged city. The world outside the city was full of temptation and hope, while the world inside the city was full of contradiction and loneliness. The novel depicted the difficulties and choices people faced in marriage, career, education, and so on. At the same time, it also revealed the complexity and contradiction of human nature. Through the fate of an ordinary person, the novel reflects the various problems and contradictions of Chinese society at that time, showing the complexity and variety of human nature, which has high literary value and social significance.