This paper aims to propose an excitation force model for multiple people jumping up and down that considers timing offset. Initially, we conduct a measurement of the excitation force waveform of the jumping up and down movements of three subjects using a force plate. Next, we analyze various parameters, starting with the timing offset for each jump. Finally, we analytically examine the impact on the relationship between the number of people jumping and the excitation force, and propose an excitation force model for multiple people jumping up and down that can reproduce previous results and takes into account timing offset.