Based on .NET framework, designs an online teaching resources management platform of three-layer architecture, which consists consisted of presentation layer, business logic layer and persistence layer. The system includes three sub-structures: student subsystem, teacher subsystem and resource management subsystem. The system has good security, can prevent illegal SQL injection and the critical data of users are encrypted by MD5. Meanwhile it has strong portability, scalability and maintainability, and achieves good results in actual application.