In view of the emergency events in stock markets, this paper firstly proposes an emergency decision-making method based on the third generation prospect theory with four reference points. Then we propose a fast information aggregation method that can change the individual prospect values into comprehensive ones quickly and efficiently, where the individual values are based on the four reference points respectively. Finally, we change the comprehensive prospect values into the form of expected ones under various scenes, and take them as the criterion of choosing emergency strategies. The results of numeral case show that: The expected prospect values based on the four reference points are more accurate to reflect the decision-making process of investors, comparing with three reference points, two reference points or only one reference point; The information aggregation method can aggregate the individuanl prospect values more quickly, and the expected ones developing from the comprehensive ones also can better reflect the reality; The proposed decision method is better than the ones based on equal weight or the ones based on complex aggregation algorithms in emergency decision for stock investment.