This paper conducts a comprehensive investigation into the pivotal parameters influencing the growth of aluminum nitride (AlN) crystals through the physical vapor transport (PVT) method. It emphasizes the analysis of various factors, including material geometry, gas flow dynamics, temperature gradients, and sublimation rates, on the crystal growth process. Utilizing numerical simulations and theoretical analyses, the findings reveal that the distribution of gas flow velocity within the crucible is notably influenced by the proximity between the materials and the crucible wall. A excessively narrow distance can result in uneven gas flow velocity, thereby disrupting the stable growth of crystals. By optimizing the relative height between the crucible and the heater, and augmenting the chamfer radius, one can effectively enhance the uniformity of gas flow and stabilize the temperature field. These adjustments improve mass transport efficiency and facilitate the homogeneous growth of crystals. Furthermore, meticulous control of the temperature gradient is imperative to mitigate excessive sublimation and crystallization phenomena, thereby sustaining an optimal crystal growth environment. This study offers theoretical underpinnings for refining the AlN crystal growth process and proposes a suite of practical optimization strategies. These findings provide invaluable insights for enhancing crystal quality and growth efficiency.