The invention relates to a feeding device, in particular to a quantitative feeding device for mixed powder processing. The technical problem to be solved is to provide the quantitative feeding device for mixed powder processing, which can avoid being affected with damp and reduce manual workload. According to the technical scheme, the quantitative feeding device for mixed powder processing comprises a first supporting frame, a first protection frame, a containing table, a distance sensor, a fixing frame, a discharging box, a heating and drying mechanism, an anti-solidification mechanism and the like, the first protection frame is arranged on the upper portion of the first supporting frame, and the containing table is arranged on the front side of the first protection frame; a first distance sensor is arranged on the right side of the lower portion of the placing table, fixing frames are arranged on the upper portion of the placing table in a bilateral symmetry mode, a discharging box is arranged between the upper portions of the fixing frames, a heating and drying mechanism is arranged on the upper portion of the placing table, and an anti-solidification mechanism is arranged between the discharging box and the placing table. The fixing device rotates to make contact with the material containing tool, the material containing tool is limited, and the situation that when mixed powder falls down, the material containing tool is unstable and topples over is avoided.