To enhance the dispersibility and photostability of AgCl nanoparticles (NPs), AgCl NPs were firmly anchored on the surface of attapulgite (ATP) to prepare the ATP-AgCl composites. The microstructure, crystal structure, and antibacterial activity of the ATP-AgCl composites were investigated. Results demonstrate that the introducion of ATP not only avoids the agglomeration of AgCl NPs, but also decreases their particle size from 5–10 μm to 3–20 nm. Due to the small size effect of NPs, the antibacterial activity of as-prepared ATP-AgCl composites is comparable to that of pure AgCl. The antibacterial ratios against Escherichia coli and Staphylococcus aureus are 99.98% and 99.88%, respectively. Additionally, the introduction of ATP also improves the photostability of AgCl NPs: the composites remains offwhite after exposure to sunshine for 24 h.