Abstract: According to the main factors influencing on the landslide stability and combined with the main indexes for evaluating pipeline failure risks, this paper establishes a multi-level evaluation system for failure risks of long-distance gas pipeline in landslide area. Based on the extension theory, and combined with the analytic hierarchy process, it establishes a multi-level extension evaluation model, and obtains the risk class of different sub-indexes and provides a comprehensive risk class for evaluated objects. Taking a long-distance gas pipeline of West-to-East Gas Pipeline in Zaoshuping District, Shaanxi Province as a case, it obtains the failure risk class of the pipeline under landslide disaster is3.18, closer to the "Danger" class and the risk classes for environmental geology and meteorology and hydrology are high, but the emergency response risk class is the lowest. In the multi-level extension evaluation, the authors consider the influence of correlation and weight of indexes in different levels in comprehensive way, which can reflect the "risk class" of evaluated objects in a more objective way.