The variance of user interest is a significant factor for designing peer-to-peer content-based retrieval system which leads to the birth of this paper. This paper gives the preliminary scheme to solve the problem of web search of Internet scale. All the personalized peers form an interest-oriented web server union (IOWSU) by employing structured P2P routing mechanism. After a query request from a peer is posted to the union, an optimized and deterministic result based on the search peer's interest is returned from the union. The result of our simulation demonstrates the method proposed in this paper is practicable and efficient.