The utility model discloses a but draw casting device on grain refinement, including the foundry furnace who is used for holding metal liquid draw the casting machine on, and set up in cooler and feed liquor pipe in the foundry furnace, wherein, on draw the casting machine set up in the top of cooler, the feed liquor pipe certainly the bottom of cooler penetrates the cooler is fixed, feed liquor socle end is sealed, the lateral wall is all has upwards offered at least round feed liquor hole, and every ring of feed liquor hole is provided with a plurality of feed liquor hole, every the axial in feed liquor hole with the inner wall of feed liquor pipe is tangent towards same direction. Above -mentioned casting device and casting process, metal liquid are spirally when managing through feed liquor hole entering feed liquor, metal liquid forms strong convection and realizes the stirring, restricts and destroys dendritic growth, does benefit to grain refinement, the metal liquid of spiral entering makes the temperature gradient of crystallization forward position metal liquid be spiral distribution, and the grain growing is the hand of spiral, realizes the spiral distribution of crystalline grain.