This paper proposes a novel approach to synthesizing nanoparticles of multicomponent oxides. The approach is based on joint electrical explosion of wires made of various metals/alloys in oxygen-containing atmosphere. Under conditions of the electrical explosion, the formed nanoparticles cool at a high rate (∼107 K/s), allowing the obtaining unique compositions based on metals with significantly different thermodynamic parameters. By the example of the (FeNiCoCrCu)xOy composition, the paper examines the effect of the energy input into the wires (E/ΣEs), the chemical composition of the buffer gas (Ar+25 % mol. O2, N2+25 % mol. O2, He+25 % mol. O2), and the ratio of metals in the wire explosion products on the phase and dispersed composition of the formed nanoparticles. It has been established that under conditions of the joint electrical explosion of wires made of Nikrothal 60 and NiCo 29-18 alloys, and Ni, Fe, Cu metals in an oxygen-containing atmosphere, nanoparticles of multicomponent oxides with crystal structures of both spinel and rock salt are formed. It has been shown that increasing the E/ΣEs from 1.24 to 2.4 results in a reduction of the average particle size from 270 to 146 nm. An increase in the thermal conductivity of the buffer gas results in a decrease in the average nanoparticle size and an increase in the content of the rock salt phase. Variation of the diameters of wires makes it possible to obtain nanoparticles with the required ratio of metals.