AgCl nanocrystals with cubic, spherical and octahedral morphology, and tunable size of 0.3–2μm have been successfully prepared by a one pot hydrothermal method using cetyltrimethyl ammonium chloride (CTAC) as Cl− source and stabilizer. Besides, the unconventional plate-like AgCl particles can be obtained by the addition of polyvinyl pyrrolidone (PVP). Photocatalytic tests show that the as-prepared AgCl photocatalysts with cubic, octahedral and plate morphology all exhibit stable photocatalytic efficiency, and the plate AgCl nanocrystals exhibits higher photocatalytic activity than cubic and octahedral AgCl nanocrystals owing to its high-index facets, stacking faults and twin defects, making it a promising photocatalyst applied in environmental management.