When a submarine earthquake occurs, pressure sensors deployed on the seafloor can record the pressure variations induced by the earthquake. Currently there is no quantitative application for utilizing earthquake-induced pressure variations. In this study, SPECFEM3D program was employed to construct a numerical model of a submarine earthquake, and simulate the rupture process and the associated seafloor pressure variations. The spatial distribution characteristics of the seafloor pressure signals were analyzed. The results indicate that at stations far from the source region, the low-frequency pressure p induced by the earthquake and vertical acceleration a of the seafloor satisfies the theoretical relationship p = ρha. In areas near the source, this theoretical relationship no longer holds, and the transition boundary between these two regimes is related to the earthquake source depth. If other source parameters are the same, such as magnitude and rake, the source depth determines the permanent seafloor deformation, which provides valuable insights for assessing tsunami threat potential. Additionally, it is found that Rayleigh waves can be recorded outside a certain range of the source region, and the pressure variations caused by Rayleigh waves exhibit an amplification effect compared with seismic body waves. The locations of stations where Rayleigh wave amplification occurs are also related to earthquake source depth, providing useful insights for tsunami early warning.