In order to explore the dynamic response of concrete slab on elastic foundation, laboratory experiment and numerical analysis are carried out. After the tested soil is filled in model box and the precast concrete slab placed above, the motion process, the void status and the shape of deflection basin are studied by using the hammer with a rubber head as the loading facility. The results show that the downward displacements of loading point reach the maximum and minimum values respectively when hitting at the corner and the center of the slab. In the case of no void, the downward displacement of hitting point is the largest, while the maximum upward displacement can be observed at the other end of the symmetry axis when hitting at one end of slab symmetry axis. The reciprocal theorem of work is completely satisfied under the conditions of small deformation and perfect contact between slab and foundation. The boundary of deflection basin is near the middle of slab when knocking at the center of slab edge, while it is in the vicinity of the diagonal when hitting at slab corner. The displacement contours near the void region get dense and their curvatures accordingly become large. The void phenomenon of the slab can be identified according to the shape of deflection basin or the displacement of related point, and the elastic modulus of foundation can be determined via fitting the numerical results with the experimental data.