The invention relates to a novel material with ultra-high 
thermal conductivity for a hot-
stamping die. The steels in the market for the hot-
stamping die are mainly various types of improved H13 and H11 high-
alloy hot work die steels. The steel in the invention comprises the following compositions in percentage by 
mass: 0.150-0.35% of C, less than or equal to 0.25% of Si, 0.08-0.20% of Mn,1.0-2.0% of W,2.0-4.5% of Mo, less than or equal to 0.30% of Cr,less than or equal to 0.02% of V and the balance of Fe and inevitable 
impurity elements, wherein S in the 
impurity elements is less than or equal to 0.005%, P in the 
impurity elements is less than or equal to 0.01 and O in the impurity elements is less than or equal to 30 ppm (parts per million). The invention is characterized in that simple elements i.e. C, Mo and W are used as the main elements, and proper proportion of 
carbide is adopted; the contents of Mn and Cr are maintained low, and the content of Si is maintained ultra-low; the steel has superior 
machining property after being subjected to electro-
smelting, electro-
slag remelting, annealing, high-temperature homogenization, 
forging and annealing; through 
thermal treatment (1060-1100 DEG C 
quenching and high-temperature annealing), the 
toughness of the steel can reach the 
toughness of common hot-
stamping die steel such as H13, and the 
hardness, annealing stability and the fatigue property of the steel are more superior; particularly, the steel with lower coefficient of 
thermal expansion and ultra-high 
thermal conductivity is more suitable for 
hot stamping.