The invention discloses a method for cooling a furnace body of a titanium-slag smelting direct-current electric-arc furnace. According to the method, a furnace casing is formed by combination of no less than one cooling module, a cooling water channel is arranged inside each cooling module and is in a bent disk-shaped structure, one ends of cooling water channels are connected with a cooling water inlet (1), and the other ends of cooling water channels are connected with a cooling water outlet (2). The method has the advantages of being capable of effectively cooling the furnace wall to form a slag adhering layer and preventing refractory bricks of the furnace wall from being corroded by melt.