This paper presents a numerical investigation into the dynamic behaviors of fluid flow through an elliptical cylinder. The lattice Boltzmann method is implemented in the direct numerical simulation. The aspect ratio (AR) varies from 0.25 to 1.0, and the attack angle (α) ranges from 0° to 90°. The numerical results were thoroughly validated by comparing them with both the experimental and numerical results. Consequently, the behavior of vortex formation is complex and depends on both AR and α. Moreover, the vortex formation regime changes significantly; i.e., the steady wake (pattern I) disappears, the Karman wake (pattern II) shrinks, and the Karman wake with the downstream secondary wake (pattern III) extends toward the higher AR. The results indicate the numerical method’s superiority in effectively capturing the vortex structure of the incompressible fluid flow in potential uses, such as heat transfer, bridge cables, offshore structures, and pipe racks.