Abstract: In order to investigate the influence of cup interference on its mechanical behavior, the cups for DN800 pipeline was taken as the research object. By analyzing the mechanical properties of the polyurethane material, a two-dimensional axisymmetric finite element model of the cup was established for analyzing the cup interference of Pigs. Through the calculation and analysis, the change trends of lip contact stress, lip contact length, the clamping end angle, the lip angle and the stress in the inner and outer of the turn were obtained in the interference at 0-10%. At the same time, the relationship between the interference and the above parameters were obtained by fitting. The research shows that the downward trend of the lip stress gradually changes from exponential decline to linear decline as the cup interference increases; the growth rates of the lip contact length and the clamping end angle increase rapidly with the cup interference increases; the growth rates of the inner and outer stresses of the turn both decreases as the interference increases; the lip angle decreases linearly with the increase of the cup interference.