Abstract: Selection of shiptypes based on PSO group decisionmaking method with multiobjects was researched. First, at the foundation of multiobjects decisionmaking method which utilizes weighting distance to ensure the consistency of decision result, a new multischeme, multiobject group decisionmaking method was proposed. Then the individual evaluation value was adjusted by PSO, making the decision result keep the initial predilection of every expert and the fine consistency of interestrelevancies. And the new method was introduced to the process of shiptypes’ optimizechoice, then to determine the important factors and their weights, a series of shiptypes was generated by equality design, and numbers of experts were invited to make a strategic decision for achieving the decision result of best shiptype. This decision method offers a new simple and efficient avenue to optimizechoice of the shiptypes with high reliability.  

Key words: group decision-making with multi-objects, consistency of decision, particle swarm optimization（PSO） arithmetic, ship-types&rsquo, optimize-choice