The invention relates to a data management method, in particular to a software-as-a-service (SaaS) software data model realization method. The SaaS software data model realization method is based on the sharing mode of a shared database, and comprises the following steps of: 1, metadata definition, namely, dividing metadata into two types consisting of a data dictionary and spatial data, and identifying the metadata by using a field in a database table; 2, generation of a basic space, namely, collecting universal data to form the basic space; 3, generation of each new space, namely, filling the basic data of each new space, copying data from the basic space into a current space and simultaneously sharing the data of the data dictionary; and 4, cross-space use of a single user, namely, registering each user into at least one space, accessing all registered spaces after the login of the user, and judging the identification field of the spatial data to enable the user to view current spatial data.