Liu Cixin is a domestically recognized "essential Sci-Fi" writer, whose works have the cultural character of "engineering practicism" and carry grand narratives and ultimate questioning. Its specific manifestations include: the pursuit of the beauty of engineering creation, the value of engineering practice based on historical rationality, and the pioneering and enterprising engineering strategic thinking. This not only enables Liu's Sci-Fi to show a calm Chinese style and a calm and rational modern style, but also enriches the dimension of exploring the relationship between man and nature in science fiction, and embodies the cultural spirit of China's rapid industrialization process. "Engineering practicism" is an important factor for the realization of the social responsibilities of science fiction in Liu Cixin's works, and it also helps to understand the substantive internal unity of some textual conflicts in his scientific writing.