Web prefetching is emerging as a promising technology and attracts many attentions from industry and research domains. researches have intensively explored many web prefetching related problems sush as prediction model, prefetching control and performance indexes. however, existing approaches emphasize on how to make use of users browsing information to predict the next request, the technologies on the framework of online web preteching are not intensively explored. it's obvious that these fundamental technologies are also very important for the succesful application of web prefetching. to address this problem, this paper present a framework for developing the only proxy-based web prefetching, analyzes the technologies included in this framework, and present the design decisions and solutions. finalyy, a prototype system based on the framework is implemented and proves the framework is effective.