This report mainly uses the input-output table data of Beijing since the 21st century, and adopts input-output analysis method and social network analysis method to study the correlation characteristics and dynamic changes of Beijing's cultural industries since the 21st century. The results show that there are close connections among the industries in Beijing, and the cultural industry occupies a relatively core position in the whole industrial network, but the core degree is not high. In terms of industrial correlation, the cultural industry has the strongest forward and backward correlation with itself, and its development has a snowball effect. At the same time, the backward correlation degree with leasing and business service industry and the forward correlation degree with computer service industry gradually increases, and the cultural industry has a stronger role in promoting the development of the tertiary industry. In terms of industrial spillover effect, Beijing's cultural industry is easy to be driven by other industries but difficult to drive the development of other industries. It has the characteristics of "intermediate industry". In general, its correlation degree with other industries has declined, and it is gradually transforming into a relatively independent industry dependent on its own development. This report argues that to achieve high-quality and sustainable development of the cultural industry, it is necessary not only to ensure the development of the main upstream and downstream industries, but also to improve the degree of integration of the cultural industry, and further improve relevant laws and regulations to reduce plagiarism and low-creativity works within the cultural industry.