The invention discloses a pourable top casting type device for casting a directional solidified steel ingot, which effectively produces the steel ingot with compact and pure inner part. The device comprises a pourable chassis, a water-cooled bottom row, a heat-insulating steel ingot module, a top casting bifurcated water gap, a slag sprinkling-resistant frame, a temperature-preserving cover, a water cooling system and a slag jar. The device casts the steel ingot by means of top casting, solves the problem of impurity caused by scouring a fireproof material, has simpler module-preparing and demolding technology than a bottom casting method, can repeatedly use the water gap, saves the fireproof material, overcomes the problems that the molten steel scours the chassis and is splashed caused by the conventional top casting method, leads the molten steel to be evenly and fast paved on the whole chassis, and leads a molten steel jar sliding water gap to be easily centered with the top casting bifurcated water gap. The device is particularly suitable for casting the directional solidified flat steel ingot to meet the quality requirement of special thick boards.