This study investigates the etching behavior and microstructural evolution of Cu-Ti alloys under different solution treatment conditions. By employing advanced characterization techniques such as electron backscatter diffraction (EBSD), scanning electron microscopy (SEM), and atomic force microscopy (AFM), the effects of grain size and crystallographic orientation on corrosion and etching surface morphology were systematically analyzed. The findings reveal that smaller grain sizes lead to more uniform etched surfaces due to reduced etching rate differences among grains, whereas larger grain sizes amplify these differences, resulting in non-uniform surface morphologies. Grains oriented near the {111}Cu plane exhibited faster etching rates, while grains oriented near the {100}Cu plane demonstrated higher corrosion resistance. Additionally, the role of twin boundaries as low-energy, corrosion-resistant interfaces was confirmed. This research provides critical insights into optimizing grain structure to achieve superior mechanical properties and enhanced surface uniformity for precision etching applications in advanced manufacturing.