The invention discloses a resin sand winnowing machine. The resin sand winnowing machine comprises a primary ventilation pipe, a secondary ventilation pipe, a primary baffle plate, a primary drop plate, a primary adjusting plate, a primary ash receiving hopper, a secondary baffle plate, a secondary drop plate, a secondary adjusting plate, a secondary ash receiving plate, a sand receiving hopper, an ash outlet and a sand outlet, wherein the primary ventilation pipe is arranged on the left external upper side of the resin sand winnowing machine; the secondary ventilation pipe is arranged just below the primary ventilation pipe; the primary baffle plate is arranged above the primary ash receiving hopper; the secondary ash receiving hopper is arranged below the primary ash receiving hopper; the ash outlet is formed at the lower part of the primary ash receiving hopper; the secondary baffle plate is arranged above the secondary ash receiving hopper; the horizontally arranged primary drop plate and the vertically arranged primary adjusting plate are arranged at the right side of the primary baffle plate; and the horizontally arranged secondary drop plate and the vertically arranged secondary adjusting plate are arranged at the right side of the secondary baffle plate. The resin sand winnowing machine provided by the invention adopts a double-stage ventilation winnowing structure, thus, the ventilation wind force is strong, the winnowing effect is good, and the problem that sand and dust are hard to separate is solved completely.