This paper fuses the techniques such as semantic network, the individuality service and agent, and references various research achievements of semantics Web on knowledge expression, RDF data manipulation and semantic retrieval, to propose an information retrieval model by combination of semantic with keyword based on multi-agent. Furthermore, each part of functions and the retrieval method were introduced, and the data mining algorithm of user profile, inquiry word, documents similar computational method, the communication way of agent and non-agent were discussed in detail.