The invention provides an electrochemical additive repairing and remanufacturing method of a damaged metal part. The method comprises the following steps of: step S1: performing three-dimensional scanning on the damaged part, and obtaining a three-dimensional entity model of a defective portion of the part according to an original three-dimensional entity model of the part, step S2: performing hierarchical slicing treatment according to certain thickness, dividing the three-dimensional entity model of the defective portion of the part into a plurality of two-dimensional graphs that are sequentially superimposed and have certain thickness, step S3: manufacturing a mask with a corresponding shape and thickness according to the two-dimensional graphs, and step S4: depositing a metal graph layer corresponding to the mask on the damaged part layer by layer by an electrochemical deposition method till a three-dimensional metal entity of the defective portion of the part is formed on the damaged part. The electrochemical repairing method of the metal part can achieve precise and quick repairing of the damaged metal part.