For characteristics of Marine scientific data, such as multi-source, massive data and network centralized management, studies on data security become a central problem. A common practice in controlling access to sensitive data is Role-Based Access Control (RBAC). Current RBAC researches focus on developing new models or enhancing existing models. In our research, we developed an RBAC model using Flex and C# as the target language, which can provide flexibility to the marine data management. Focusing on data security, the paper gives the layer architecture and the model design of security access management for specification. The paper also presents the detailed methods to achieve data security by the technologies of identifying validation, verifying codes, access control, preventing illegal users and database security by oracle parameters and storage procedures. Additionally, we have conducted an empirical study to evaluate its usefulness and effectiveness. All the methods adopted in this paper can be applied in data management of various systems.