Abstract: A theoretical analysis on oil leakage accident in Cangzhou-Linyi Oil Pipeline is made by means of checking calculation on allowable stress and equivalent stress, combination stress and stability of pipeline. The results show that the combination stress (σ_z)of the pipeline is 243. 5MPa, more than 210. 6MPa, the allowable stress σ of the pipeline, while the deformation value in horizontal direction in diameter of pipeline is more than 3%. In this case, the fracture of pipeline is inevitable.