After an analysis by means of expressing the supersymmetric charge in terms of particle's creation and destruction operators，we find the conditions，under which supersymmetry on the bound state of a Supersymmetric field-Theoretic Bag model represents finite dimensions. From these conditions，we get the rules of choosing wave functions for particles inside bound state. uhich will largely simplify the task of finding bound state of the model. Examples are given to show the new features of such notation in comparison with "off such" notation. The possibility of describing leptons and quarks by a Supersymmetric Field-Theoretic Bag model is also discussed.