The invention relates to an RIA-based high-performance Web transmission network management system and an implementation method thereof. The Web transmission network management system comprises a Web browser arranged on a client; the Web browser downloads a rich client application program from a Web server to a local computer through an HTTP protocol, and runs the program off line or on line; the Web server comprises the rich client application program, a Web data service layer, a Web services layer, a business logic layer, a data access layer and a system integration layer. The system and the method are applied to a telecom transmission network management system by effectively using an RIA architecture and rich client technology, and run the network management client with strong operational function on the Web browser of a main flow. The Web transmission network client has various complicated graphical user interfaces, supports local refreshing interfaces, directly performs synchronous or asynchronous interaction with a server, receives data pushed by the server in real time and can fully use computation resources and storage resources of the local computer.