Abstract: The unstructured P2P network becomes more and more popular with the easily global deployment and supporting fuzzy key match，but the unstructured P2P network has poor scalability because of the flood broadcasting.This paper puts forward a balanced binary tree as the unstructured P2P network topology structure based on the existing problems of the unstructured P2P network topology structure，designs the corresponding algorithm of network peer insert，leave，and resources search，and shows the improved results by corresponding simulation.

摘要： 非结构化的P2P网络由于方便的全局部署和支持模糊匹配，而越来越受到欢迎，但是非结构化的P2P网络采用了洪泛的广播方式，因而导致网络的缩放性比较差，该文则在研究非结构化P2P网络拓扑结构存在问题的基础之上，提出采用平衡二叉树作为非结构化P2P网络的拓扑结构，设计相应的网络节点加入，节点退出，资源搜索等算法，并通过相应的仿真来展示改进的效果。