The invention discloses an ultrasonic homogeneous mixing-proportioning device of multi-element metal powder. The mixing-proportioning device is composed of operating function components such as a mixing tank, a plate-type ultrasonic transducer, a vacuum air pump, a metal powder spraying feeder, a mixing disperser, a hydrogen injecting pump, an automatic control device. According to the mixing-proportioning device, the advanced power ultrasonic dispersion technology and the traditional mechanical atomization spraying stirring-mixing technology are combined. The mixing-proportioning device has a plurality of operating functions such as atomizing, spraying, vibrating, refining, dispersing, homogenizing, stirring and mixing. A plurality of elementary substance metal powder can be mixed and proportioned to be the multi-element metal alloy powder in one-time mode, and the multi-element metal alloy powder is accurate in component control, homogeneous and sufficient in dispersion, even in constituent element distributing, standard in particle size, and moderate in particle looseness. The mixing-proportioning device has the advantages of being advanced in technology, complete in functions, easy to operate, reliable in performance and the like. The mixing-proportioning device can be widely applied to powder metallurgy industry, and carries out dispersion and homogenous stirring and mixing on the various elementary substance metal powder.