Abstract: The theory of social network and the harvest of trust models are researched.After combining of the trait of the internet business and social network，and taking the trust decay brought by time，risk rank and the close degree of the relationship between nodes into consideration，and a trust computing model that combines these factors is built.After the simulation，boast problems can be efficiently identified，and this model also can refrain the behavior that nodes use the small scale business to accumulate the trust value，in order to cheat in the big scale business.A simulation result shows the feasibility of the model.

Key words: social network, trust model, simulation

摘要： 研究了社会网络的原理以及现有信任模型的研究现状，并在此基础上结合网络交易和社会网络的特点，考虑了时间带来的信任衰减、交易风险等级、关系紧密程度等因素，建立了基于社会网络的互联网信任模型，通过计算结点间的信任值来衡量信任程度，仿真实验表明该模型能有效地识别出自夸点，能够防止通过小额交易积累信任值，之后进行大额交易欺骗的行为。仿真结果表明，该模型具有可行性。

关键词: 社会网络, 信任模型, 仿真