With the number of long-distance pipelines increasing in China, risk management has become important for controlling pipeline leakage. However, all the current assessment technologies are semiquantitative and do not include inspection data. To address this problem, a new quantitative risk assessment model is proposed to guide decision-making on excavation inspection and maintenance. Based on previous failure cases, the model includes data about the surrounding soils as well as about the pipeline's protective layer, cathodic protection (CP), and pipe wall thickness readings. Testing of the proposed model on previous failure cases shows that the new model can correctly assess the real leakage risk of a long-distance pipeline and support the quantitative integrity management of a long-distance pipeline during its whole service life.