Abstract: In order to study the load time history characteristics and pressure distribution law of high pile cap foundation under wave current, the pile cap composite foundation of a sea crossing bridge is numerically simulated. According to Stokes second-order wave theory, wave generation in numerical pool is carried out, and Reynolds averaged Navier stokes equation (RANS) is used to solve the fluid motion equation. The hydrodynamic time history and surface pressure distribution of each part of high pile cap foundation under three submergence coefficients in the range of 0~1 are calculated. The volume of fluid function (VOF) is used to track the liquid surface shape and simulate the wave shape time history. The results show that: (1) When the submergence coefficient is large, the horizontal force of the cushion cap is large and mainly comes from the combined action of wave and current; the diffracted waves in the wake area will produce negative horizontal force and negative buoyancy force; there is an extreme pressure fluctuation region on the upstream and downstream of the cushion cap. (2) With the decrease of submergence coefficient, the horizontal force of cushion cap decreases, and the horizontal force is mainly wave beating force; the vertical buoyancy force and the horizontal force of single pile increase accordingly; the diffraction effect in the wake region is reduced; the fluctuation area of extreme pressure of bearing platform is reduced until it disappears. (3) The maximum positive horizontal force of the pile foundation appears in the last row of piles on the side column; the maximum negative horizontal force appears in the last row of piles in the middle column. The research on the total force history and pressure distribution law can provide a reference for optimizing structural design.