The current social network analysis method is essential in dealing with massive data on network relationships. By treating individuals, organizations, or countries as nodes and their relationships as connecting lines, the network diagrams provided a new perspective for studying social structure and communication paths. When exploring the path of Chinese national culture, the spatio-temporal network model can better analyze cultural diffusion’s dynamic characteristics and efficiency, and then optimize the diffusion strategy to promote the global diffusion of Chinese culture. In this study, the efficiency and characteristics of cultural diffusion are analyzed in depth using social network analysis, with indicators such as point degree centrality, mediated centrality, proximity centrality, and network flatness. The effectiveness of cultural diffusion is influenced by the identification of critical nodes and the trust propagation mechanism in the normalized model. Estimated by the generalized least squares method, the model demonstrates the increased efficiency of cultural dissemination under specific dissemination attributes and narrative attributes, in which the average number of plays of Chinese cultural content on the TikTok platform reaches 13,585,700, the number of likes reaches 355,123, and the number of comments is 31,398. Enhancing the global communication efficiency of Chinese national culture can be achieved by optimizing the social network structure and content strategy. This study provides a scientific basis and practical guidance for spreading Chinese culture globally, and emphasizes the importance of social platforms in cultural dissemination.