To　study　the　separability　of　quantum　states　in　multipartite　quantum　systems,　the　classification　of　multipartite　quantum　separable　states　was　presented　by　using　Bell　inequalities.　These　inequalities　can　well　distinguish　all　possible　k-separable　states　in　2⊗2⊗2⊗2⊗2　systems,　including　fully　separable,　bi-separable,　tri-separable　and　four-separable　states.　Using　the　generalized　Bell　operator　and　the　classification　of　genuine　entanglement,　applying　the　Cauchy-Schwarz　inequality,　the　linear　programming　and　other　methods　in　mathematics,　the　authors　give　out　the　upper　bound　of　absolute　value　for　the　average　values　of　Bell　operator　to　achieve　the　classification　of　separable　states　in　multipartite　quantum　systems.