The invention discloses a high-strength pump valve. The high-strength pump valve is prepared from 3.5-5 parts of C, 1.5-2 parts of Mn, 0.5-1 part of Si, 12-14 parts of Cr, 3-5 parts of CU, 0.3-1 partof Sn and 30-40 parts of Fe. A preparation method of the high-strength pump valve includes the following steps that 1, the raw materials are put in a heating container to be heated to 1,500-1,900 DEGC, all the raw materials are melted into solutions, the solutions are mixed to be uniform, pouring liquid is formed, and finally the pouring liquid is poured into a forming die; 2, the forming die issealed and does not make contact with external objects, the forming die is taken out after being naturally cooled, and the pump valve has a preliminary appearance; and 3, the prepared pump valve appearance is put in a grinding forming device to be ground, leftover materials outside the pump valve appearance are removed, and the joint of the die is smooth. The grinding forming device is convenientto use, easy to operate, suitable for pump valves with different sizes and shapes, convenient to adjust and high in grinding efficiency during use.