FeNiCuMnTiSnx multicomponent alloys (x = 0, 0.05, 0.1, 0.5, and 1 where x denotes the adding amount in atomic percentage when other elements are taken as 1) are prepared by an arc furnace. The results show that the crystal structure of FeNiCuMnTiSnx alloys transforms from mixed intermetallic compounds to a single crystal structure (zinc blende structure) with the increasing of Sn content. The magnetization of the FeNiCuMnTiSnx alloys gradually increases from 0.34 to 15.8 emu · g−1 with the increasing x, the magnetic transformation undergoes from the paramagnetism (x= 0, 0.05, 0.1) to superparamagnetism (x= 0.5) finally to soft magnetism (x= 1) at room temperature. We use computer simulation and find that the magnetism of alloys appears when Fe atoms replace Ni atoms.