The invention relates to a shaping device for quantitatively feeding down feather, which comprises a leveling mechanism (1), an evenly fluffing mechanism (2), a down feather feeding mechanism (3) and a fixed mechanism (4). A fixed frame of the fixed mechanism (4) is a trilateral frame provided with a rightward opening, and the leveling mechanism (1), the evenly fluffing mechanism (2) and the downfeather feeding mechanism (3) are connected to a fixed block of the fixed frame (4) in sequence from left to right. The method comprises the following steps: the leveling mechanism (1) delivers down feather with set thickness and square meter quality to the evenly fluffing mechanism (2); the evenly fluffing mechanism (2) fluffs the down feather with set thickness and square meter mass into the down feather feeding mechanism (3) according to inclination; and the down feather feeding mechanism (3) quantitatively feeds down feather according to the set thickness and square meter mass. The methodfor quantitatively feeding down feather has high control precision and high feeding efficiency.