The invention discloses a high-performance economical wear-resistant steel plate and a preparation method thereof. The steel plate comprises the following components by the weight percentage: 0.20-0.30% of C, 1.60-1.80% of Si, 0.30-0.60% of Mn, not more than 0.015% of P, not more than 0.010% of S, 0-0.030% of Ti, 0.20-0.50% of Cr, 0-0.30% of Ni, 0.05-0.20% of Mo, 0.0010-0.0030% of B, and the balance Fe and inevitable inclusions. The preparation method comprises the processes of smelting, casting, slab furnace charging, slab heating, rolling and heat treatment. The steel plate has the product hardness reaching the level of HBW430-480, is low in cost, and has both excellent cold bending property and welding performance.