The informal geological data devote to the inconvenience of the management and retrieval, so to meet the of practice application, this paper take the geological prospecting companies for example and sort out the equal relations of the geological prospecting companies, focus on the construction of the equal relations of the geological prospecting companies to improve the retrieval recall. By training a small amount of corpus and studying some examples to summarize and classify the equal relations of geological prospecting companies, and it is extended to the domain knowledge debase constantly. The semi-supervised classification algorithm based on domain knowledge database is designed and implemented by using the domain knowledge database and the semi-supervised classification learning method. In the case of significant recognition, taking further manual intervention on algorithm preliminary identification results, and ultimately reach 92.83% recognition results, it has improved the geological exploration units in the name of geological data in the database search results, which has good scalability and reusability.