Most metamaterials consist of a solid medium, whereas research is lacking on fluid-solid metamaterials (FSMs). Water storage tanks in sponge cities can be considered periodic structures or FSMs and can be used for wave isolation. However, the wave propagation properties of FSMs are unclear. A finite element analysis model of metamaterials was established using COMSOL software based on the periodic theory. The dispersion curves, frequency response functions, and vibration modes of the FSMs were determined. Mechanism analysis of the bulging vibration and Bragg scattering characteristics of the FSMs was conducted, considering fluid-solid coupling and the vibration modes. A periodic water container (PWC) sample was used as the FSM, and dynamic tests were carried out to verify its inhibitory effect on the P-wave propagation. The results showed that the proposed FSM could excite the bulging modes, blocking the propagation of the elastic longitudinal waves and converting the energy of the structure into the bending energy of the wall plates. It could attenuate the elastic longitudinal waves in two extremely low-frequency ranges. The water improved the vibration damping capacity of the FSM, reducing the lower bound frequency of the initial Bragg scattering attenuation zone and enlarging the attenuation range. This study provides a new concept for designing water storage devices to reduce environmental vibrations at certain frequencies. The new device can have a broad impact in advanced vibration reduction measure.