Abstract: Because of lacking for uniform international standard and network topology model，the P2P network presents a confusion environment all along.This paper start form“The Small World Model” and the users’ interesting，gives a new P2P topology model IGP2P，which based on interest grouping.By the idea of grouping，each group will be grouped by a central node.For the purpose of reducing the harm for the network by single point failure，a new strategy SCNS is put forward.And bring cache into IGP2P，not only enhance searching speed rate and successful rate，but also it does good job to the network’s stability.