The invention discloses a preparation method of a multi-layer grade structure copper alloy material. Double-groove electrodeposition technology is adopted, a copper plate serves as a matrix material;metal Cu and metal Ni are alternately deposited between two electroplating grooves, and a component-modulated Cu/Ni multilayer film is formed; and the electroplated Cu/Ni multilayer film is carried out surface nanocrystallization treatment so as to prepare the multi-layer grade structure material with high strength and high plasticity. According to the method, the strength of the multi-layer gradestructure copper alloy material prepared by the method is more than 2 times or above of the strength of a multi-layer copper alloy, and good plasticity can be kept; and the multi-layer grade structure copper alloy material has important value and application space in the rapidly developed fields of automobile, aerospace, electronics and the like.