In order to achieve an intelligent information retrieval system, we must fully understand the contents included in the retrieval conditions. The flexibility of natural language and different perspective to a matter of different persons would lead to different expression forms or different meanings of the same concepts. It has a great impact on the retrieval recall factor and pertinency factor of the information retrieval. Usually, the query request of the users is a simple word or phrase, when the system receives the query request, it needs to process them in the semantic level. According to the characteristics of network technology, the top-level retrieval model is as figure 3.