In zinc electrodeposition, deposit morphology and thickness uniformity are governed by the coupling of current distribution, ion transport, and interfacial reactions. In this study, a three-dimensional transient finite-element model was established using COMSOL Multiphysics based on the tertiary current distribution framework. The model coupled ionic transport, charge conservation, interfacial electrochemical reactions, and deposition-thickness evolution to analyze Zn2+ and H+ concentration fields, current distribution, and deposition behavior. Simulations were performed under different flow rates, anode-cathode spacings, acid-zinc ratios, and current densities. The results showed that 250 ml min(-1), 20 mm spacing, an acid-zinc ratio of 3.4, and 600 A m(-2) provided a preferred operating window by balancing Zn2+ supply, H+ accumulation, and zinc growth. Experimental observations agreed well with the simulation trends.