The invention discloses a knowledge graph construction method and system and a storage medium. The method comprises the steps: collecting initial learning data, storing the initial learning data in alearning resource database, and carrying out the ontology term extraction and marking of the initial learning data according to a subject teaching outline and teaching materials; inputting the relationship and sequence between each meta-knowledge point, constructing a directed subject knowledge graph through an ontology editor, generating an OWL file, and storing the OWL file in a learning systemin the form of a triple; updating and inputting the learning process state data of the user in real time, and performing multi-knowledge-point modeling on the learning process state data of the user through a DKT algorithm to obtain a learning and mastering state of the user; According to the learning and mastering state of the user, mining the relationship among the knowledge points, and dynamically updating the subject knowledge graph. According to the method, the DKT is tracked based on deep learning, so that a multi-knowledge-point modeling scene is effectively solved, the latest knowledgemastering state of a learner is accurately detected, the knowledge graph is constructed, and the internal relation of knowledge points is obtained.