Abstract: 【Purpose/significance】Under the background of big data, the evolution of network public opinion in sudden public events presents new characteristics. Based on the background of big data, studying the evolution of network public opinion in sudden public events can provide theoretical and practical references for the governance of network public opinion in sudden public events.【Method/ process】Using evolutionary game research methods, construct an evolutionary game model for the stakeholders of sudden public event network public opinion under the background of big data, analyze the relationships between various factors that affect the evolution of sudden public event network public opinion under the background of big data, and how big data affects the evolution process of sudden public event network public opinion.【Result/conclusion】The research results indicate that the evolution of public opinion in the con⁃ text of big data is influenced by multiple factors. The quality of public opinion information in big data directly affects the evolution of public opinion in the context of sudden public events. The speed of public opinion dissemination in the context of big data also affects the strategic choices of the main body of public opinion evolution in sudden public events.【Innovation/limitaion】The evolution of on⁃ line public opinion during sudden public events is also influenced by costs, reward and punishment mechanisms, etc. Only when big data management agencies, governments, and media actively cooperate can the optimal evolution be achieved.