It’s simple technology to manufacture big trimming die by hardfacing on the die insert of steel. In this paper, a kind of surface hardfacing technology which deposited by using D322 on 42CrMo steel were studied instead of traditional manufacturing process. The effect of hardfacing parameters on microstructure, hardness and wear resistance are tested and analyzed. The key points of manufacturing trimming die by using hardfacing method was given out. There are no defects in the hardfacing layer. The average hardfacing layer is higher than 57.5HRC. The hardfacing surface has good figurations and hardfacing layer has good wear resistance. The hardfacing for real product of trimming die is completed successfully and their properties reach or exceed those of dies made with traditional technology. This technology is also an effective approach of repairing other cold working dies. The experimental results indicate that the hardfacing technology has much more advantages, cheaper than that of traditional process. The wear resistant test of hardfacing layers were carried out by using different welding current. The best welding current for hadfacing 42CrMo steel is 110 Ampere. The wear mechanism of hardfacing layer is belongs to abrasive wear model.