The invention provides a steel splitting device for a cooling bed. The steel splitting device comprises cooling-bed fixed racks and cooling-bed movable racks, which are alternatively arranged in sequence, wherein steel splitting toothed plates are fixed at the inlets of the cooling-bed fixed racks and/or the cooling-bed movable racks and used for dividing tooth space of at least two teeth at the inlets into at least two parts. According to the steel splitting device, rolled steel can be effectively prevented from being stacked on the cooling bed in a bar production process, the product quality can be improved, the product yield can be increased, and the effects of reducing the cost and improving the efficiency are achieved; the steel splitting device has the advantages of simple structure, small volume, low cost, flexible steel splitting form and convenience for dismounting.