Cloud computing is a technology that enables elastic, on-demand resource provisioning. In multi-tenant shared data storage model, how to achieve dynamically scalable data storage is the key of cloud data management. For the issue of how SaaS applications adaptively scale with the change of the quantity of tenants and request, on the basis of analyzing scalability requirements of the data storage layer, based on Walraven et al. proposed multi-tenant architecture, we extend the typical cloud application architecture, and design a multi-tenant data management framework, achieving scalability of storage resources. Based on the framework, a SaaS prototype system for network management is developed, verified its validity and availability.