In the context of new era,digitalization of education has become an inevitable choice for the future development of higher education,and acts as a pivotal strategy for the construction of high-quality education system.The digital transformation of the public se-curity education can facilitate its modernization.As an important carrier of deep integration between artificial intelligence and education,knowledge graph associated with online courses plays an key role in the digitalization of public security education.The online course of criminal investigation should be constructed based on the advantages of online courses and the characteristics of knowledge graph.This paper elaborates the general idea,construction method,integration of the third-party knowledge and feedback of the application,so as to provide reference for the construction of online courses in police colleges.