The utility model relates to an aging thermal treatment device for a copper alloy under DC. The device comprises a thermal treatment furnace which is provided with a conducting wire for connecting a copper alloy sample to be treated and (with) a DC power supply. Because the aging thermal treatment device for the copper alloy under DC is provided with the conducting wire, the motions of vacant sites inside the copper alloy sample are influenced by the DC, and the vacant sites are gathered around a dislocation and a crystal boundary to provide a nucleation site for a precipitated phase; in addition, the DC has influences on energy barriers required to be overcome in the precipitation of solid solution atoms from a copper matrix and further has influences on the quantity and distribution of aging-precipitated second phases to control the structure of the copper alloy, so that the copper alloy has excellent comprehensive mechanical performance; thereby, the aging thermal treatment device for the copper alloy under DC solves a problem that the high strength and high electrical conductivity of the copper alloy cannot be incompatible.