Using a self-designed vertical Bridgman (VB) furnace, a growth furnace model was established through dynamic simulation and experimental deep coupling iterative optimization method. The optimal temperature field of the growth furnace was obtained by optimizing the temperature field, and the actual temperature field was optimized and modified based on the simulated optimal temperature field. 3-inch (1 inch=2.54 cm) diameter gallium oxide (β-Ga₂O₃) single crystal was successfully grown in this paper. 2.5 inch (100) plane β-Ga₂O₃ wafers were successfully fabricated from the as-grown crystal. The crystalline quality and optical properties of β-Ga₂O₃ crystal were characterized and tested. The test results indicate that, the β-Ga₂O₃ crystal has high crystalline quality, with cut-off edges of ultraviolet for (100) plane is 257.5 nm, corresponding to an optical bandgap of 4.78 eV. The Laue diffraction spots of the crystal are clear and symmetrical, with a minimum full width at half maximum (FWHM) of the rocking curve at 39.6″.