In order to effectively solve the problem of grey state in the process of oil and gas pipeline safety management, the evolution process of oil and gas pipeline safety risk is analyzed based on the risk source theory, and a safety management model for oil and gas pipeline system is constructed. The model is composed of three workflows in series: security risk identification, security risk early warning and security risk control. Based on the factual attribute of hazard source, the reasonable or approximate reasonable result of risk identification is deduced by using the uncertainty transfer algorithm and the extended generation rule in combination with the risk database. By using the extension theory, the warning level is divided into four levels: no alarm （N1）, low alarm （N2）, medium warning （N3） and high warning （N4）, and qualitative analysis and calculation of oil and gas storage and transportation risk warning are performed. Using Java programming language and Oracle database technology, a safety management platform for oil and gas pipeline system is designed, including safety risk identification, safety risk warning, safety information management and other functional modules. The research findings show that the introduction of uncertainty theory can effectively solve the subjective and fuzzy problems of risk identification in the process of oil and gas storage and transportation. According to the calculation of the extension risk warning model, the characteristic value of the level variable of the tank is 2.0404, which belongs to the low warning range. The obtained results are in good agreement with the actual work area. The method of information management makes up for the defects of empirical management and provides good technical support for the integrity of risk data and safety emergency decision.