The invention relates to a metal-based ceramic reinforcement body for a grinding disc of a vertical grinding machine and a preparation method of the reinforcement body. The reinforcement body is a fan-shaped board body, wherein an arc-shaped notch and an arc-shaped projection which correspond to each other are respectively arranged on two sides of the board body. The reinforcement body is of a mixture formed by integrally sintering the following components by weight percent: 10% to 40% of corundum and 60% to 90% of iron powder, wherein the particle diameter of each corundum particle is between 0.25cm and 0.35cm. The preparation method comprises the following steps: evenly mixing the corundum particles and the iron powder which are prepared in advance; sending a mixture into a sintering kiln; sintering at a certain temperature until the iron powder is completely molten; then putting the sintered mixture in a mould which is prepared in advance; and cooling and demoulding so as to obtain the metal-based ceramic reinforcement body. According to the method, the energies at the tip ends of cracks are consumed through the plastic absorption of the iron powder with the addition of load during the sintering process, so that the reinforcement body and the grinding disc or a grinding roller can be connected to form an integrated structure by casting molten steel in the hole of the reinforcement body.