Abstract: In order to comprehensively improve the efficiency of railway duty work, standardize the operation mechanism of operations, and strengthen the construction of digital duty system, this paper designed a task ontology architecture for duty in response to problems such as information overload, important information being ignored, and inability to quickly index target content that occur during the duty process of railway authorities, implemented efficient organization and reconstruction of duty tasks. The paper comprehensively analyzed the scenario of multiple duty tasks and used the Protégé semi-automatic ontology construction tool to implement the task ontology construction of the railway duty. The instance mapping of the ontology verified the feasibility and scientificity of the ontology construction method. This achievement helps to promote the standardization and normalization of railway duty work, improve the response speed of transaction handling, enrich the knowledge system of duty, and provide important basic support for the application of knowledge graphs in the field of duty and decision-making assistance.