Environmental emergencies are associated with great harm, sudden onset and high publicity and cause serious damage to a broad range of ecological environmental, human health and social properties in a short period of time. Environmental decentralization can help local governments strengthen their independence and make better use of the advantages of environmental information to curb the occurrence of environmental emergencies, but regional corruption significantly weakens its effectiveness. Therefore, based on panel data of China's 30 provincial administrative regions between 2005 and 2016, this paper applies the panel threshold model to explore the relationship between environmental emergencies, environmental decentralization, and regional corruption. The results indicate that, first, environmental decentralization, environmental administrative decentralization, environmental monitoring decentralization, and environmental supervision decentralization all have a negative influence on environmental emergencies; second, as the degree of corruption in a region increases, the effect of environmental decentralization on restraining environmental emergencies decreases; and finally, there is heterogeneity in the relationship between environmental emergencies and environmental decentralization in various regions. Environmental decentralization in the eastern and western regions negatively affects environmental emergencies, while there is a positive relationship between the two in the central region.