There were many reasons for Yu Dafu's tragedy. The following are some possible reasons: 1. Social environment: The era that Yu Dafu lived in was a turbulent period. War, political change, social unrest and other factors caused people's psychological and social instability. In such a social environment, the fate of an individual was often affected by various factors such as social status, family background, personal ability, and so on. 2. Personal personality: Yu Dafu's personal personality was also one of the reasons why he fell. He pursued freedom, independence, a strong personality and self-awareness, but he also had shortcomings such as overconfidence, combativeness, and conceit. These shortcomings made him prone to self-indulgence and self-torture. 3. The influence of literary works: Yu Dafu's literary work, Sinking, was also one of the reasons for his sinking. The story of an individual suffering injustice and bullying in society was widely used in the literary world and society at that time. Yu Dafu's works were regarded as a reflection and accusation of social reality. 4 Personal experiences: Yu Dafu's personal experiences were also one of the reasons why he fell into depravity. He had experienced family poverty, lack of education and other difficulties. These experiences had a profound impact on his personal outlook on life and values, and also made him pay more attention to social reality and the injustice of personal destiny. To sum up, Yu Dafu's tragedy was caused by many factors. Whether it was the social environment, personal personality, literary works or personal experiences, all of them had a profound impact on his fate.