Resin sand die

The utility model provides a resin sand die and adopts the technical scheme that the resin sand die comprises a top molding box, a bottom molding box, resin sand, a cavity formed inside the resin sand, and a runner for communicating the cavity with the outside; the resin sand is filled with rigid filler materials. A resin sand layer is filled with the rigid filler materials, and on the premise of not influencing a casting, the using amount of the resin sand is reduced greatly, and the rigid filler materials can be repeatedly and circularly used, so that the cost is reduced greatly; in addition, hollow steel balls are adopted, so that the using amount of the materials is further reduced, and the cost is further reduced.