The utility model discloses an agricultural automatic mixing apparatus of backward flow formula, the agitator tank lower part is equipped with down the hopper, and upper portion is equipped with the backward flow and fights, and the agitator tank lower part still is equipped with the discharge gate, the conveyer belt connects material conveyer belt low side to accept at least including connecing material conveyer belt and backward flow conveyer belt the down export of hopper connects the low side of the high -end linking of material conveyer belt backward flow conveyer belt, the high -end linking of backward flow conveyer belt the import that the backward flow was fought. Backward flow formula structure make throw in the preparation of nutrition soil, fertilizer and matrix the flich just, stirring, occupation of land be little, equipment investment simultaneously is less, it is convenient to maintain. It uses to be suitable for the peasant household.