A twodimensional geometry model of hydride vapor phase epitaxy (HVPE) growth chamber with the diameter of 15.24cm (6inch) was established to simulate the growth of Ga2O3 material. The key parameters were optimized, such as the inlet velocity of GaCl and O2 and the distance between the nozzle and the substrate. The uniformity of the thickness of Ga2O3 film on the substrate reached 7.02% at a relatively high growth rate. In addition, simulation experiments were carried out under different reactive activation energy parameters. It is found that although the activation energy parameters affect the average growth rate significantly, they have little influence on the optimal design of growth rate distribution and uniformity of the samples.