Preheating device for cold rolling

The present invention provides a preheating device for cold rolling, capable of preventing fracture of a plate during cold rolling during the winter. According to the present invention, the preheating device for cold rolling comprises: a heating chamber heating an object to be heated; a hot air supply unit heating air and supplying the air to the heating chamber; and a spray unit including a bored body, a spray plate connected to the body to rotate, a plurality of diffusion protrusions protruding from the spray plate, and a plurality of spray nozzles passing through the spray plate wherein the spray unit connects the hot air supply unit and the heating chamber.