With the development of communication technology, the concept of cross-cultural narrative is constantly mentioned in academia and the communication industry. This study used the Marvel Universe's 'The Infinity Saga' series, a phenomenon network that just ended, as an example to understand the process of expanding the story network of cross-media narrators. Through research, this article concluded that the Marvel Story Universe has a story extension and media extension due to 'intermediary', which makes the overall story appear fluid / unshaped. Story nodes can form text clusters, cooperate with each other to deepen the knowledge base, and continue the narrative brand. The Marvel Story Universe is a narrative brand for ten years, which has been transformed into performances such as video, interactive games, and theme parks. Cross-media narrators use narrative economies such as images and video to continue to stimulate readers to participate in story opportunities. This is a narrative strategy for expanding the story network . Another reason is that the cross-media network can extend the front, branch, and back from the mother to shape the 'story node'. Cross-media narrators consider the needs of potential audiences through “intermediary” and “cross-media gaps”, triggering the involvement of potential audiences, and hoping that potential audiences can move between different story nodes and text clusters. This is the way to expand the media network. Narrative strategy.