Corrosion has a certain effect on the mechanical properties of pipe steel. In this paper, tensile tests were carried out on pipeline steels with different degrees of corrosion, and the relationship between the mechanical properties and corrosion loss of pipeline steels with different degrees of corrosion was studied. Based on the test results, a numerical analysis model was established to analyze the stress state at the corrosion pit. Under the action of axial tension, the fracture position of the pipeline steel with corrosion defects occurs at the corrosion pit with the largest aspect ratio. The results show that the yield strength and elastic modulus of pipe steel with surface corrosion defects have a low correlation with corrosion loss degree, but the yield load and equivalent elastic modulus decrease obviously with the increase of corrosion degree. The maximum depth to width ratio of the corrosion pit is the main factor affecting the stress concentration factor at the corrosion pit. The research results can be used to evaluate and predict the mechanical properties of pipelines in service, and provide an analysis basis for the prevention of pipeline leakage and life cycle.