The frequent occurrence of extreme weather disasters in recent years poses new challenges for disaster governance. Through the examination of public participation in an online collaborative editing document in the 2021 rainstorm rescue in Zhengzhou, this article explores the process of self-organizing communities achieving collaborative governance in disaster relief through media. The research results indicate that serial participant in self-organizing communities is a core element contributing to the success of rescue efforts. Firstly, serial participants successfully increased the probability of converting victims in need to victims rescued by acting as network intermediaries and shortening the interaction distances between participants. Secondly, it is precisely because of the solutions of supply and demand matching, resource deployment, accelerating the flow of information, connecting multiple actors proposed by serial participants, that the interest reconciliation and joint action between multiple stakeholders, including the state, the market and the public, can be realized. Finally, as a response to China’s strategic goal of deepening the modernization of governance systems and governance capabilities, this article discusses the characteristics of mediatized governance in disasters, and how governance innovation based on digital media technology can optimize efficiency.