When traditional full-text searching technologies based on keywords are applied on government information, low quality results will be return. It is helpful to express searcher’s meaning more completely by combining traditional full-text searching technology with ontology technology. Quality of information retrieval will be improved. A detailed solution is proposed. Later method of designing government ontology utilizing domain oriented thesaurus is discussed. How to use combined words with high frequency to assist searching is also discussed. At last a case verifies that it is right.