Because of the characteristics of complicated decision2making problems , it is very difficult to describe and solve complicated decision2making problems only by the means of quantitative models. From the viewpoint of Metasynthetic Engineering , the paper holds the opinion that the solving process of complicated decision2making problems requires the support of multifaceted model . According to the cognition levels of complicated decision2mak2 ing problems , the paper puts forward that the multifaceted model systemof complicated decision2making problems is composed of concept model , structure model and mathematics model and then elaborates the three kinds of models