In order to study the influence of vertical loads on the dynamic response of pile group foundation in liquefiable ground, the high cap pile group is taken as the research object. The shaking table test is used to take 5%, 10%, 15% and 20% of the ultimate vertical bearing capacity of the pile foundation as the vertical load, and the test is carried out under the seismic intensity of 0.20g, 0.34g and 0.50g. The effects of different vertical loads on sand liquefaction and dynamic response are analyzed from aspects of pore pressure ratio time history, acceleration time history, pile cap displacement time history and pile bending moment response time history. The results showed that with the increase of vertical load, the peak pore pressure ratio and the liquefaction degree of sand decreased. The peak values of pile top acceleration, pile cap displacement and pile bending moment decreased first and then increased with the increase of vertical load, and the values were the smallest when the vertical load was 15%. The increase of vertical load can inhibit the liquefaction of sand and increase the inertial force of the structure. With the combined influence, the dynamic response effect of pile group in liquefiable ground is optimal under the vertical load of 15%.