Corrosion damage is an important factor causing structural failure in offshore engineering. In order to study the effect of local corrosion on the bearing property of H-shaped steel used in offshore structure, a random pitting damage model of H-shaped steel was established with the regular cylindrical pit model and the method of MATLAB random number generation, taking H-shaped steel column as the research object. The influence of pitting position, pitting pit diameter and depth ratio on the bearing property of H-shaped steel is obtained by eigenvalue buckling analysis and double nonlinear analysis respectively. The results show that the reduction degree of bearing capacity is the most serious when the pitting corrosion is at Y4 position. When the diameter-depth ratio changes, the larger the diameter-depth ratio is, the less obvious the stress concentration is, and the less the impact on the bearing capacity is. When the depth is constant, the greater the ratio of diameter to depth, the more obvious the stress concentration and the greater the influence on the bearing capacity. The research results can provide some reference value for structural safety performance assessing.