Abstract: The melting and electromagnetic stirring processes in metal smelting furnaces offer significant advantages, including rapid homogenization of temperature and composition in molten metal, reduced melting time, improved product quality, and lower production costs. In this study, a multifunctional variable-frequency power supply based on power conversion technology is designed, which is capable of driving both single-phase melting coils and three-phase electromagnetic stirring coils. First, the load characteristics, main circuit topology, and modulation strategy of the dual-function power supply for single-phase melting and three-phase electromagnetic stirring are analyzed and designed. Then, based on the load parameter characteristic table, detailed calculations of each component of the main circuit are carried out, and the overall main circuit design is completed. Finally, a prototype is developed, and the proposed multifunctional variable-frequency power supply is applied to drive a 5-ton smelting and stirring furnace with stirring capability, thereby verifying the feasibility of the proposed scheme.