Spudcan is the foundation of jack up platform, which plays a role in supporting and stabilizing the whole jack up platform. In the process of "stepping on the footprints" of jack up drilling platform, the bottom of spudcan is subjected to uneven bearing capacity of soil, which may cause excessive local stress of spudcan and lead to damage of spudcan. In view of the potential danger of the "footprints" of the jack up drilling platform to the spudcan structure, the "footprints" test model of the jack up drilling platform with three legged is designed, and the pressure distribution at the bottom of the spudcan at different mud entry depths is obtained. Through analysis, it is found that when the mud entry depth is 5m, the maximum pressure difference occurs at both ends of the spudcan, while when the mud entry depth is 15m, the pressure at the bottom of the spudcan is the largest. A quadratic polynomial function is constructed according to the pressure distribution value at the bottom of the spudcan corresponding to different mud entry depths. On this basis, a detailed finite element model of the square spudcan is established by using the finite element software ABAQUS, and the constructed pressure distribution function is applied to the bottom of the spudcan according to the distribution law, The stress results of spudcan at different depths and eccentricities are calculated. The results show that in the process of "stepping on the footprints", the maximum stress occurs in the circular pipe at the top of the spudcan and the shell plate at the bottom. The force imbalance on both sides of the bottom of the spudcan has a great impact on the strength calculation of the spudcan. Compared with the conservative calculation method of directly applying the maximum ballast to the bottom of the spudcan, this method and calculation results are closer to the actual engineering conditions.