Risk assessment is an important content and basis of pipeline integrity management. With the continuous progress and development of the integrity management of oil and gas field gathering and transmission pipelines, the lack of mature risk assessment methods for nonmetallic pipelines has become increasingly prominent. Based on the analysis of failure risk factors of non-metallic pipelines and statistical results of failures in an oilfield, a semi-quantitative risk assessment method based on the Kent method for non-metallic oil and gas transmission pipelines was established. The evaluation index of failure possibility includes 49 evaluation indices from five aspects:third-party damage, operating environment, design, manufacture and construction, mal-operation and geological hazards. The failure consequence indicators covers 6 aspects, including short-term damage caused by the medium, maximum leakage of the medium, dispersion of the medium, the affected parties, social impact, and the impact of supply interruption on downstream users, with a total of 12 specific evaluation indicators. The failure probability index weighting coefficient and evaluation index score are optimally determined by expert scoring method. This risk assessment method of non-metallic pipelines lays a foundation for the implementation of risk assessment of non-metallic gathering and transmission pipelines in oil and gasfields.