The invention discloses a bothway powder paving powder based additive material manufacturing device and a powder paving method thereof. A lifting mechanism is connected to the lower portion of an additive material manufacturing molding cylinder, the left side and the right side are each provided with a powder recycling cylinder, the powder recycling cylinders are symmetrical, and a left automatic powder feeding mechanism and a right automatic powder feeding mechanism which are symmetrically distributed are arranged right above the additive material manufacturing molding cylinder; and an automatic powder paving mechanism is connected with a powder paving assisting guide rail in a sliding manner through a movable sliding block arranged on the powder paving assisting guide rail in the left-and-right direction, and the automatic powder paving mechanism can conduct powder paving and compaction on powder. The powder paving method includes the following steps of powder feeding, paved powder compaction, high-energy beam sintering, paving of a second layer of powder, powder compaction and high-energy beam sintering; and the above steps are repeatedly executed until a molding piece is machined completely. The bothway powder paving powder based additive material manufacturing device and the powder paving method have the beneficial effects that back-and-forth powder paving during same powder paving is achieved, so that the efficiency is improved; as for paving of special powder materials, alternative powder paving between layers can be achieved, quantified powder feeding can be achieved, and the powder supply amount is reduced; the powder is preheated, and powder agglomeration can be reduced; and different kinds of powder can be recycled.