Abstract: With the development of space technology, people pay more and more attention to the use of space data. Space data cannot be accessed without any restriction. So the access control models of space data are becoming more and more important. This is also a hot spot in current research in the world. Presented in this paper is an STS-RBAC model, which is an improvement of traditional RBAC model. STS-RBAC model is based on the spatial database operations and it includes the attributes of space, time and scale. It can also be used in vector data and raster data. This model can manage the problems of multi-scale spatial objects as well. Scale, as is all known, is a basic element in the security of spatial data such as time and space. STS-RBAC model focuses on the special character of spatial data, and introduces role hierarchies based on the constraints of position and time, which guarantees the reliability in spatial database access. STS-RBAC model also defines the transmissibility and partial order in permissions, which makes it possible that authorizations can be inferred from others. This decreases the time and space when spatial database is accessed. With the help of STS-RBAC model, it is possible to access spatial data more efficiently and securely.