SaaS 作为新的软件模式，以本地部署、互联网访问的方式向客户提供服务，降低运维成本。本文在研究传统 RBAC 模型的基础上，结合SaaS 多租户、可配置、个性化的特点，提出一种SaaS 系统下分层的访问控制模型，实现系统多租户、 个性化服务的功能,给出实现方案和设计原理。

SaaS as a service is a new software mode which deploy the application on the local server and provides application software service for customers through the Internet. Based on the study of the traditional RABC mode and combined with the characteristics of multi-tenant, configurability and personality, the author of this article has designed a hierarchical mode of SaaS system for access control model. It achieves the function multi-tenancy and personalized service of system and then provide the design proposal and the implementation principle.