A green inorganic antibacterial material was prepared using shell waste as a carrier material loaded with silver. It was characterized and analyzed by X-ray diffraction (XRD), scanning electron microscopy equipped with an energy dispersive spectrometer (EDS), X-ray photoelectronic spectroscopy (XPS) and N-2 adsorption isotherms. The antibacterial activity was evaluated using Staphylococcus aureus and Escherichia coli as sensitive indicator strains. The antibacterial mechanism was probed and discussed as well. Silver carbonate was detected in the prepared material through XRD analysis. XPS measurement and EDS analysis also confirmed the loading of silver onto the carrier. The antibacterial test demonstrated that the prepared material had good antibacterial property, especially against E. coli. Based on the silver ion release and pH test, as well as comparatively analyzing the characteristics of carrier material and prepared material, we proposed that the antibacterial mechanism mainly involved the antibacterial activity of silver ion, slightly higher pH value and supplementary photocatalytic antibacterial activity of silver carbonate.