This article addresses a class of multi-stage, multi-scenario, multi-department emergency decision-making processes, considering psychological preferences and interdepartmental collaboration. Based on prospect theory, some new matrices such as indicator scenario value matrices and comprehensive scenario value matrices are constructed. Under the framework of constant interval, an emergency decision-making matrix method is proposed to evaluate developments in a comprehensive manner, thereby achieving scientific and efficient decision-making. The article presents the matrix form of prospect value calculation, making it programmable to effectively cope with the dynamics of multi-stage emergencies (departmental and scenario changes), thus enhancing decision-making efficiency. The constant interval is introduced to describe the psychological tolerance of decision-makers, and the influence of positive and negative changes in the constant interval is further discussed to optimize the emergency decision-making process. For example, when the tolerance increases, although it does not change the relationship between the magnitude values of each scenario, it may affect the choice of the optimal solution, while in certain situations, it does not have an effect. Finally, an analysis of a chemical plant case study confirms the effectiveness of this matrix method and demonstrates its valuable application in handling such emergency decision-making situations.