The emergency management information system can provide visual scene rendering when emergencies happen and assist the decision-makers to make reasonable decisions. Because of the limitation of emergencies' extreme conditions, the decision-makers should make effective decisions to the utmost. However, the premise of the highly effective decisions of the decision-makers is that they can choose the scene rendering which matches with the mission requirements. This study conducted two researches and found that the decision-making performance of scene rendering in which the decision-maker's independent choice matches the mission requirements is relatively low, while when there is support from the Decision guidance, the decision-making performance is relatively high. This study will discuss the research result as well as the influential factors, and then provide support for the design, scene rendering as well as the follow-up studies of decision-making performance of the emergency management information system.