In order to promote understanding mechanisms of co-seismic response of water level in well shaking table experiments have been carried out with sinusoidal loading in different vibration frequencies and amplitudes （accelerations） for complete well unconsolidated confined aquifer system. The physical model has been built based on experimental model, and fluid-solid coupled model of pore pressure response in unconsolidated aquifer and mathematical model of flow interaction between aquifer well under vibrations have been established. The experimental processes have been simulated in COMSOL Multiphysics, a multi-field coupling simulation software. Four typical water level variation forms observed in experiment are similar to those of field studies, and the results of numerical simulation show that the mathematical model established in this study can well reflect the response of pore water pressure and water level in unconfined aquifer. This research is of great significance to explain the mechanism of co-seismic responses of groundwater, and stability and safety of seepage in rock and soil mass.