The invention discloses a thick gold electroplated copper based workpiece and a manufacturing method. The manufacturing method comprises the steps of pretreatment, bottom nickel layer electroplating,18K gold layer electroplating, 23K gold layer electroplating, stress removal, tinting, and antitarnish coating treatment. A surface shell of the thick gold electroplated copper based workpiece sequentially comprises a bottom nickel layer, a 18K gold plated layer, a 23K gold plated layer and an antitarnish coating from inside to outside. The manufacturing method comprises the steps that before thick gold electroplating, bottom nickel electroplating treatment is carried out, after thick gold electroplating, annealing treatment is carried out, antitarnish coating treatment is carried out on the surface of a thick gold plating, prepared electroplated thick gold is bonded with a copper base firmly, peeling is not easy, the service life of a gold cladding is prolonged, the cladding is uniform and compact, and attractive in color, and a good oxidation color changing prevention property is achieved.