Provided is a method of preparing an aluminum-resin complex in which an aluminum alloy and a resin composition are integrated with each other. More particularly, the present invention is relates to a method of preparing an aluminum-resin complex having improved bonding strength by preparing an aluminum alloy having a more uniform etching surface using an alkaline aqueous solution to which a chelating agent and a cycloamine are added and an acidic aqueous solution to which a chelating agent is added and injection-molding a resin composition using the aluminum alloy.