It is necessary to study the stress and its influence factors of buried pipelines which are under uneven settlement in order to ensure the safe operation. Stress measurement was taken on 3 representative testing points on pipelines and the pipelines' stress in operation was obtained. The nonlinear contact model of pipe and soil was built by using ANSYS. By analyzing the model, pipelines stress was obtained and the mapping relationship of the settlement with the maximum Von-Mises stress was set up. Based on this model, the influence of diameter, wall thickness, burial depth, soil's elasticity modulus and Poisson's ratio on the stress status of pipelines were also studied. Increasing wall thickness and soil's elasticity modulus and decreasing burial depth and diameter can reduce the maximum Von-Mises stress of pipelines under uneven settlement. The research methods and achievements may offer basis and measures for further researches on mechanical characteristics of natural gas pipelines under uneven settlement.