Based on the self-assembled equipment, the properties of Ga2O3 films prepared by atomization-assisted chemical vapor deposition (AA-CVD) method were studied. The effects of temperature and pressure difference on the crystal qualities of Ga2O3 thin films were studied by X-ray diffraction. The results show that there is a phase structure conversion process of Ga2O3, upon the temperature improving from 425 ℃ to 650 ℃, the crystalline structure of the thin films transform from amorphous structure, pure α-Ga2O3 crystal structure to α-Ga2O3, β-Ga2O3 two-phase mixed crystal structure. The effects of temperature on the thin films’ surface morphology were characterized by atomic force microscope. When the temperature increases from 475 ℃ to 650 ℃, the root-mean-square roughness of the thin films surface decrease from 26.8 nm to 24.8 nm. At the same time, the single crystal property of the α-Ga2O3 thin film was measured by high resolution X-ray diffraction. The result shows that the thin film sample having a full width at half maximum of only 190.8″ which prepared at the temperature of 475 ℃ and at the pressure difference of 5 Pa, it can prove that the α-Ga2O3 film is a highly crystallized single-crystal materia.