Electrochemical additive manufacturing technology has garnered significant attention for fabricating micro/nano metal structures due to its high precision, low porosity, and elimination of thermal stress. This paper presents a method for additive-regulated electrochemical microjet 3D printing of copper structures, optimizing process parameters. It first analyzes the impact of additive components on copper crystallization. Then, it theoretically derives the deposition rate on the cathode surface and investigates energy transfer and material transport during deposition using numerical simulations. The process parameters are initially screened through Taguchi experiments, illustrating their interactions. Based on these results, response surface experiments further refine the parameters and clarify their interrelations. Utilizing the optimized parameters from both Taguchi and response surface experiments, 3D printing of copper microcolumns of varying sizes and spiral structures is conducted, resulting in an average surface roughness of 0.065 μm for the different-sized columns, and a range of 0.106 μm to 0.159 μm for the spiral workpieces. The experimental findings confirm that additive-regulated electrochemical microjet 3D printing technology can accurately produce complex metal 3D structures and components, presenting promising engineering applications.