The global automotive industry is accelerating its transition toward low-carbon solutions, with hydrogen fuel cell vehicles offering core advantages of zero emissions and extended range. Their critical component is the Type III fiber-wound hydrogen storage tank, whose performance directly impacts vehicle operational safety and driving range. This technology has now achieved widespread adoption. However, two significant challenges persist in the dome region of these tanks: first, modeling accuracy is difficult to control due to dynamic variations in thickness and winding angles; second, fiber thickness buildup frequently occurs near the pole holes. These issues compromise both the design reliability and manufacturing quality of hydrogen storage tanks. Therefore, this study adopted a combined approach of theoretical analysis and numerical simulation. First, based on composite mechanics theory and calibrated with experimental data (Tensile, Compression, and Shear Tests on NOL and Unidirectional Plates), the design methodology and key material parameters for the hydrogen storage tank were determined. Subsequently, through secondary development based on ABAQUS, rapid and high-precision finite element modeling was achieved. Results from the progressive damage model were validated against hydrostatic burst tests, controlling prediction errors within 3%, effectively resolving the modeling accuracy issue. Simultaneously, to address the fiber buildup problem, this study innovatively proposed two process solutions: bandwidth-based hole expansion and extreme-value hole expansion. Numerical simulation comparisons demonstrated that the 1.5-times bandwidth hole expansion scheme is optimal, enhancing fiber distribution uniformity, reducing overall stress levels, and improving load-bearing capacity. These technical methods and research conclusions provide theoretical support for the design and manufacturing of fiber-wound hydrogen storage cylinders.