It is currently a global hotspot that the application of multimedia and network technology to education is coming to be. There are inevitably threats brought about by the reliance on network and security problems of different levels in the modern web-based distance education system. This paper gives introduction to and analysis on the building of network security mechanisms in detail for distance education system in three aspects, including the selection of the user authentication, VPN selection of remote communication supporting, and the server-side performance guarantees. Then a detailed solution is made.