The technology of information filtering is the hotspot in current study. This paper analyses three models of information filtering: Boolean logical model, vector space model, latent semantic indexing model, and points out their defects.In order to purify the information of the Internet, this article introduces the genetic algorithm to the network information filtering system and establishes the network information filtering model based on genetic algorithm. At last it compares the network information filtering model based on genetic algorithm with the three commonly used models. Through the result of the experiments, it is easy to see that the information filtering model based on genetic algorithm is a predominant model.