Abstract: With the continuous increase of management requirements in the field of water intake permission, the traditional information management system of water intake permission is difficult to meet the complex information retrieval needs, which restricts the improvement of meticulous management in water resources.A knowledge graph of water intake permission in the Changjiang River Basin is established to break the information silo between systems and improve the efficiency of information retrieval in water intake permission, and a knowledge graph Q & A including entity mention recognition, entity link, relational matching and other functions is proposed based on a large-scale pre-trained language model.According to the characteristics of data in water intake permission domain, BM25 algorithm is used to sort candidate entities to construct a knowledge base question answering system in the Changjiang River Basin, and a Web client is developed based on BS framework.The experiment shows that the system achieves an accuracy rate of 90.37% on the test set, which can support the retrieval needs in the field of water intake permission in the Changjiang River Basin.