In view of the low accuracy and the lack of intelligence and individuation in existing information retrieval system,the capacity of resources semantics description of Ontology and Multi-Agent,s characteristic of intelligence and individuation were used in this paper. Model of Multi-Agent information retrieval system based Semantic Web was proposed in virtue of the combination of Semantic Web and MAS. In comparison with existing retrieval model only based on Multi-Agent or Semantic Web, Intelligent Agent in our model utilizes ontology knowledge to normalize retrieval request information,which can improve the accuracy rate and cover rate of retrieval.