In order to improve the carburized layer quality and wear performance of 12CrNi3A-steel, a combined method of laser shock processing carburization is put forward. The wear performances of different samples which are directly carburized and carburized after laser shock processing are measured by the ball milling experiment. The microstructures of 12CrNi3A steel are examined by scanning electron microscope (SEM). The result shows that the wear rate of carburized after laser shock is 2.69×10-14 m3/Nm, reduced by 29% comparing with the samples carburized only. The mechanism of wear resistance improvement is discussed from two aspects. For one thing, the friction coefficient reduces by 25% after laser shock processing and carburization. For another, a large number of fine carbide particles on carburized layer are formed in the sample carburized after laser shock, and the surface carbide particles of 12CrNi3A steel are distributed in a gradient manner.