The invention provides a combined lead melting device which comprises a plurality of molten lead preparation pots, a molten lead storage pot, heat preserving pipelines and a control device, wherein the plurality of molten lead preparation pots are used for melting solid lead materials, the molten lead storage pot is arranged among the plurality of molten lead preparation pots and lead application equipment and used for providing a storage space for molten lead in the process of conveying and carrying out heat preserving and heating on the molten lead, and each heat preserving pipeline is used for connecting each first lead pump and a molten lead input mechanism. According to the combined lead melting device disclosed by the invention, through setting at least two molten lead preparation pots and a molten lead storage pot which are used for supplying lead to subsequent lead application equipment, the normal production of the subsequent lead application equipment is ensured; and the combined lead melting device is simple in structure and easy to use. In addition, the invention also discloses a production line using the combined lead melting device.