Fortress Besieged was a long novel by Qian Zhongshu, which was regarded as a classic of modern Chinese literature. The word "besieged city" was frequently used in the novel, and its meaning was also very profound. The term "besieged city" comes from a famous metaphor, which refers to a city wall trapping people between the inside and outside of the city. This metaphor hints at the dilemma and dilemma in people's lives, that is, we are bound by our own imagination and expectations, trapped in a self-limiting framework, unable to obtain true freedom. In Fortress Besieged, the word "besieged city" was used to describe the city described by Qian Zhongshu. The city was besieged in political, economic and cultural contradictions. People were trapped in the city and could not escape. This image profoundly reflected the various predicaments and contradictions in modern society, which aroused the readers 'resonance and thinking. Therefore, the meaning of the word "besieged city" in Fortress Besieged is a state of contradiction and dilemma, a feeling of being trapped in a self-limiting framework, and a feeling of being unable to escape the limitations of reality.