The invention discloses a melting furnace with a preheating device and a refining chamber. The melting furnace comprises an inner furnace shell, an outer furnace shell and an electric heating layer; abaffle is arranged in the inner furnace shell, and the inner space of the inner furnace shell is divided into a melting chamber and the refining chamber by the baffle; the outer side of the outer furnace shell is provided with a connection pipe, a discharging pipe, an air inlet pipe, an air outlet pipe and a conveying pipe, the conveying pipe is internally provided with a conveying shaft, and theconveying shafts penetrates through the end face of the conveying pipe, extends to the outside space and is connected with a driving device; and a spiral blade is arranged surrounding the conveying shaft. according to the melting furnace, the feeding mode is improved, melting chamber feeding and workpiece preheating can be conducted at the same time, heat energy is saved, and the production efficiency is improved; the refining chamber is arranged, by injecting mixed gas into molten aluminum in the refining chamber, the effect of removing aluminum oxide and hydrogen in the molten aluminum is achieved, the quality of the molten aluminum is improved, and the follow-up technology is facilitated; and an exhaust purification device is arranged, and the working environment is perfected.