To facilitate uncertain internet opinion emergency decision involved with multiple fuzzy index values, we design
a new prewarning decision system mechanism for uncertain internet opinion emergency based on case reasoning and
grey relational analysis. Through the invented software in recent patents in data mining areas we first collect the internet
opinion and detect the emergency data. Then by calculating the comprehensive grey relational coefficient between the unknown
internet opinion emergency and each source emergency case, we can easily retrieve the optimal historical case for
current emergency problem. And the related emergency managers may adopt or modify the corresponding warning decision
solution of the most matched source case to make urgent decision for the new occurred internet public opinion emergency
with uncertain indexes and incomplete weight information.