Abstract: The authors apply the Risk Evaluation method (by W. Kent. Muhlbauer) to study the risk of large and/or medium traversing and span crude oil pipelines. On the basis of the basic conception of Risk Evaluation, the paper provides Risk Evaluation method of the large and/or medium traversing and span crude oil pipelines through risk identification, grading and the evaluation criterion of risk consequences. Meanwhile, the quantitative method on the risk consequences is given and explained.