At present, ship model tests are based on the normal mode at home and abroad. With the development and application of abnormal hydraulic model, it is necessary to study abnormal ship model. The similarity criterion of abnormal ship model is deduced from the similarity theory of normal hydraulic model in this paper. Some factors that affect the maneuverability of the abnormal ship model are discussed by theoretical analysis of ship maneuvering. The influence of the K and T index of different variable rate on the abnormal ship model maneuvering and the dimensional effect of the abnormal ship model are obtained, which can be used as a reference for the study of the abnormal ship model