In this paper, the interference mechanism and influencing factors of corrosion defects in oil and gas pipelines were studied to provide guarantee for the safety of pipelines. By using ABAQUS and the double elastic slope method and the control variable method, the ultimate load of the pipelines with internal and external corrosion defects were solved when the sizes of internal and external corrosion defects (relative depth, relative length, relative width) and the axial distance of the defect are changed. The influence criterion was determined by the limit of 5% interference effect, and the limit influence distance of internal and external corrosion defects were obtained. At the same time, MATLAB was used to establish the relationship between the corrosion defects with the interference effect limit distance. Also, the formula was obtained by fitting. The constructed quaternary cubic polynomial fitting formula R2=0.9898, SSE=0.5361, RMSE=7.3219, showing low dispersion and high precision. The results show that: With the increase of depths of internal and external defects a1/t and a2/t from 0.1 to 0.3, the influence distance of the interference increases significantly from 46 mm to 193 mm, and the rate of change becomes larger and larger. With the increase of the lengths of internal and external defects and from 0.5 to 2.5, the influence distance of the interference increases continuously from 71 mm to 219 mm, but the rate of change becomes smaller and smaller. With the increase of the internal and external defect widths c1 and c2, the influence distance of the interference is unchanged. Defect depth is the most important factor affecting the interference distance, the defect length is second, and the defect width is not affected.