The present invention discloses one kind of antiwear high-boron cast steel and its preparation process. The antiwear high-boron cast steel has the chemical components including C 0.10-0.50 wt%, B 0.8-5.0 wt%, Cu 0.3-0.6 wt%, Mn 0.8-2.0 wt%, Cr 1.0-2.5 wt%, Si less than 1.5 wt%, Ti 0.08-0.20 wt%, Ce 0.04-0.12 wt%, Mg 0.02-0.18 wt%, N 0.06-0.18 wt%, S less than 0.05 wt%, P less than 0.05 wt%, and Fe and inevitable impurity for the rest. Its preparation process includes smelting in an electric furnace while adding ferromanganese, frrroboron and Al to deoxidize, composite modification of molten steel, fast cooling, and low temperature tempering to eliminate stress. The present invention has simple production process, low production cost and other advantages.