Promoting interdisciplinary development is an inevitable requirement for the advancement of science and education, as well as an internal need for disciplinary growth and a necessary choice for building world-class universities. In this paper, high-quality academic outputs from China's first-class comprehensive universities are used as a data source. Scientific methods are employed to process the data, construct an interdisciplinary cooperation network, and form a typical interdisciplinary model and central discipline. Through analysis, several key characteristics of cross-disciplines in China's first-class comprehensive universities are identified: the intersection of natural sciences dominates, while the intersection of humanities and social sciences is relatively weak; "Engineering + X" and "Management Science + X" have become common interdisciplinary models; the equations of material science and computer science give rise to interdisciplinary "all-match" disciplines; and basic disciplines play a significant role in the interdisciplinary landscape. Therefore, universities should place greater emphasis on the interdisciplinary disciplines of humanities and social sciences, strengthen the construction of "versatile" disciplines and basic disciplines, further promote interdisciplinary integration, and enhance the research and innovation capabilities of universities.