The invention provides a nitriding catalyst which is an alloy with a general formula of RTxMy, wherein R is one of rare earth metals: La, Ce, Pr, Nd, Y, Sm and the like or combination thereof, T is one of metals: Fe, Co, Ni, Mn, Ti, V, Cr, Si, Al, Mg, Sn, Zn and the like or combination thereof, M is one of interstitial elements: H, B, C, N, P and the like or combination thereof, x is ranged from 1 to 20 and y is ranged from 1 to 10. According to the nitriding catalyst provided by the invention, the temperature of gas nitriding in nitrogen-containing atmospheres such as nitrogen or ammonia gas can be remarkably reduced.