According to the characteristics of the overall scheme decision-making of warships, the improved Delphi was introduced for decisionmaking. The scheme’s sequence of group and individual decision was transformed into a Boolean matrix. The difference of group and individual Boolean matrix elements reflected the group consistency of decision-making. Then, the optimization model based on sort consistency was constructed. The initial scoring matrix was adjusted within the correction range by FIPSO to search the feasible solution that can satisfy group consistency. The credibility function was built to analyze the overall credibility of the revised evaluation, and the credibility was also taken into account besides group consistency. The comparative analysis of an application example show that the method has well optimal decision stability and decisionmaking credibility.