As found, the spreading and solidification of a metal droplet on a substrate is basic in a number of advanced and new technologies and is actively studied in the world. The mathematical apparatus for predicting internal flows and the technical means of direct observation of the rapid process of simultaneous spreading of a liquid droplet with the transition into a solid lamellar particle, in particular, under the action of a constant magnetic field, are very complicated. Because of this, the development of ways to obtain information about the evolution pictures of this process, which determines the effectiveness of the technology, becomes relevant. A technique for visualizing melt-flow pictures of an emulsified Bi–Zn alloy under the conditions of simultaneous spreading, cooling and solidification processes of a diamagnetic droplet on a non-magnetic metal substrate under the influence of a constant magnetic field is developed. Emulsified inclusions and oxide films are visualizers of pictures of internal flows of the melt, which is significantly disturbed and stratified by temperature. As found, a constant magnetic field applied perpendicular to the substrate affects the dynamics of the melt, which is manifested in a significant (up to 10 times) reduction of defects in the particle structure. The effect of the magnetic field on the structure of the alloy is determined, which is accompanied by 2 times’ increase in the homogeneity of the distribution of emulsified inclusions and the appearance of new forms of formations, which are not observed in samples not treated by the field. As shown, a constant magnetic field can be used promisingly in the fabrication of an array of droplets (coating, spray process, etc.) and single droplets (additive technologies, wetting of microobjects, etc.), as well as products from fast-cooled advanced alloys, for example, systems based on copper with iron, aluminium with rare-earth metals, prone to the formation of heterogeneous and rough structures.