The invention provides a grain mixing device, which relates to the technical field of liquor automatic production. Wherein, the grain mixing device includes: a support frame; a power mechanism, whichis arranged on the support frame; a mixing mechanism, which comprises a rotating shaft, a plurality of turning sheets, and a two-row fixed bracket, which is symmetrically arranged on the opposite sideof the rotating shaft with the central axis of the rotating axis as symmety, and the rotating shaft is rotatably mounted on the support frame, and one end of which is connected to the power mechanism, the fixed bracket is connected with the rotating shaft by a threaded connection structure, and one turning sheet is fixed on each fixed bracket. The grain mixing device can replace the worker mixing, improve the efficiency and controllability of the brewing mixing, reduce the labor intensity, and adopt symmetrical arrangement form, without unilateral accumulation of material, at the same time each fixed bracket is connected with the rotating shaft by a screw connection mode, which can conveniently change the angle of the turning sheet to achieve the best turning effect.