Rare earth hot work die steel and preparation method thereof

The invention discloses rare earth hot work die steel and a preparation method thereof, relates to the technical field of rare earth steel, and particularly belongs to the rare earth hot work die steel and the preparation method thereof. Comprising the following components in percentage by mass: 0.35 percent to 0.45 percent of C, 0.50 percent to 0.90 percent of Mn, 0.20 percent to 0.50 percent of Si, less than or equal to 0.005 percent of S, less than or equal to 0.010 percent of P, 1.3 percent to 1.5 percent of Ni, 2.80 percent to 3.20 percent of Cr, 1.40 percent to 1.60 percent of Mo, 0.10 percent to 0.18 percent of V, 0.025 percent to 0.045 percent of Al, 0.0045 percent to 0.0060 percent of La and 0.0010 percent to 0.015 percent of Ce. The invention has the characteristics of high strength, high toughness, high thermal stability and the like, and can prolong the service life of the mold, accelerate the production rhythm and obtain the positive effect of large-scale application. 稀土热作模具钢及其制备方法，涉及稀土钢技术领域，特别是属