The invention discloses a powder mixing apparatus achieving high stirring efficiency and uniform mixing of materials. The powder mixing apparatus comprises a material mixer and an electric motor arranged on the bottom end of the material mixer, wherein the electric motor is connected with the material mixer in a driving manner, the material mixer is a hollow container with the upper end and the lower end being asymmetric, the upper end and the lower end of the material mixer are in oblique circular truncated cone shapes with different inclination angles, the upper end and the lower end of thematerial mixer are respectively provided with a material inlet and a material outlet, and the material inlet is communicated with a material inlet funnel; and a plurality of stirring rods are arrangedinside the material mixer, the stirring rods are movably connected onto the inner surface of the material mixer, and the end portion of each stirring rod is vertically provided with a hammering part.The material mixer of the asymmetric structure is used for mixing powder, when the material mixer is driven by electric shock to rotate, because of the irregular structure of the material mixer, thepowder makes complex movement in up-bottom and left-right directions in the material mixer, then the stirring rods which are movably connected into the material mixer are used for stirring the powderin an auxiliary way, so that the powder is uniformly mixed, when the stirring rods swing, the hammering parts can hammer the powder, and the powder with large granularity can be crushed.