HCl-acidified attapulgite-supported platinum nanocomposite catalyst was prepared by a simple method for the selective hydrogenation of chloronitrobenzenes to the corresponding chloroanilines under relatively mild conditions. The nanocomposite catalyst exhibited excellent catalytic activity and selectivity for the selective hydrogenation of p-chloronitrobenzene, m-chloronitrobenzene and o-chloronitrobenzene. The selectivity to chloroanilines could be up to 100% at complete conversion of chloronitrobenzenes under 2.0MPa and 50°C. The catalyst structure was characterized by TEM, XPS and BET, and both the mechanism of high activity and the reason for the deactivation of the catalyst were discussed.