The invention discloses a knowledge graph-based interactive question and answer method and system. The method comprises the steps of constructing a knowledge graph, wherein data in the knowledge graphis from multiple open-source information sources; according to existing entities in the knowledge graph, forming a dictionary, forming mapping from a name to a professional field through a manual tagging method, and performing expansion in a conventional feature modeling mode to form a professional dictionary; according to the data in the knowledge graph, forming mapping from the entities to a training set of the field through the manual tagging method to establish a classifier; according to the professional dictionary, performing word segmentation on a natural question sentence through a forward maximum matching method, and according to results after word segmentation, inputting the results to the classifier for performing classification, thereby classifying the natural question sentenceinto questions in different fields; and mapping the classified questions to obtain corresponding question templates, and converting the question templates into query sub-graphs in the knowledge graph. Answer can be performed for sentences of more complex questions, so that the answer quality can be ensured and the manual intervention is effectively reduced.