Fortress Besieged was a long novel by Qian Zhongshu, which was regarded as a classic of modern Chinese literature. From the perspective of a wealthy intellectual, Fang Hongjian, the novel described his struggles and confusion in the siege, as well as his deep thoughts and reflections on marriage, love, human nature, and society. The theme of the novel was the complexity of human nature and the predicament of being besieged. Inside the besieged city, Fang Hongjian felt trapped in a contradictory situation when faced with the freedom outside and the shackles outside. He longed for freedom and love but was unwilling to give up his social status and wealth. When he faced marriage and love, he was also faced with various choices and considerations. Sometimes, it was even difficult for him to make a decision. The intention of the novel was to reveal the complexity of human nature and the realistic predicament of society through a symbolic siege. It called on people to seriously consider human nature and society, not to easily give up their own values and pursuits. At the same time, it also reminded people to cherish and grasp the present in the process of pursuing freedom and happiness.