The invention discloses a melting furnace for casting and producing high-performance Cu-Ag alloy. The melting furnace comprises a graphite crucible and graphite heating elements which are arranged in a hearth. A separated graphite diaphragm, graphite buffering diaphragms, an air blow hole and the like are arranged in the graphite crucible, and the melting furnace further comprises a horizontal crystallizer or the horizontal crystallizer and an upcasting crystallizer. The invention further discloses a device with the melting furnace, and the device is used for casting and producing a high-performance Cu-Ag alloy conductor. The invention further discloses a method for casting and producing the high-performance Cu-Ag alloy. By using the device, upcasting continuous casting production or horizontal continuous casting production can be carried out separately and simultaneously, the production is flexible, the method is not only suitable for the production of the Cu-Ag alloy but also different types of alloy, therefore, antivacuum continuous casting volume production and production cost reduction can be achieved, no molten metal remains in the crucible of the melting furnace, and copper alloy with low impurity content and uniform alloy compositions is obtained.