In Lao She's novel, Soul Breaking Spear, the image of Sha Zilong had a profound meaning in expressing the theme of the work. Sand Dragon was a character full of personality and complexity. His image showed the good and evil, contradictions and conflicts in human nature. As a Jianghu man, he had both a righteous and evil side, which made his image more three-dimensional and rich. At the same time, his image also reflected the reality and ethos of the society at that time, showing the social background and living conditions of the Jianghu people. The relationship between the image of the sand dragon and the protagonist Fang Hongjian was also very special. Sha Zilong had deep feelings for Fang Hongjian, but his feelings were also full of contradictions and conflicts. He loved Fang Hongjian but was afraid that his actions would hurt him. This complicated relationship reflected the contradiction and conflict between the emotions and social status of men and women in the society at that time, as well as the complexity and variety of the society at that time. Therefore, by portraying the image of the sand dragon, Lao She deeply expressed the theme of the work: the good and evil, contradictions and conflicts in human nature, as well as the reality and ethos of the society at that time. At the same time, the image of the sand dragon also showed the social background and living conditions of the Jianghu people, making the work more realistic and closer to the historical background of that time.