Abstract: As a knowledge base describing the relationship between research objects with explanatory language, knowledge graph can enhance the ability of machine learning and excavate the deep and hidden relationships between things to help deciders make decisions. The process and method of knowledge graph construction in oil and gas pipeline industry, focusing on business requirements, ontology design, knowledge extraction, knowledge fusion, knowledge storage and knowledge iterative updating, were put forward in combination with the characteristics of oil and gas pipelines based on the principle of knowledge graph technology. The knowledge graph of geohazard risk management of oil and gas pipeline based on risk identification, assessment and prevention was constructed according to the Specification for geological hazard risk management of oil and gas pipeline (SY/T 6828—2017) for the first time, and application demonstration was carried out based on the typical clay landslide hazard. Besides, the deduction and visualization of the decision-making process, application scenarios and decision-making results of the knowledge graph in the intelligent geohazard assessment of oil and gas pipeline was discussed on the basis of defining the logical framework of hazard risk assessment and prevention, which provides a feasible way for the intelligent aided decision-making in geohazard risk assessment and prevention for pipelines. (3 Figures, 3 Tables, 24 References)