Nanocomposite heterogeneous nanomaterials excellent optoelectronic properties have been widely used in the field of solar cells. In this research, β-Ga₂O₃@ZnO composite heterogeneous-material was successfully prepared by combining magnetron sputtering with hydrothermal method. The thickness of the surface β-Ga₂O₃ was adjusted by controlling the magnetron sputtering time, and the influence of β-Ga₂O₃ film thickness on the optoelectronic properties of β-Ga₂O₃@ZnO nanocomposite heterogeneous was systematically investigated. The morphology and microstructure of the samples were characterized by scanning electron microscope (SEM), X-ray diffractometer (XRD) and Raman spectroscopy. It is found that that the proper thickness of β-Ga₂O₃ can improve the surface morphology leading to the excellent light absorption performance. Furthermore, the band gap of β-Ga₂O₃@ZnO nanocomposite heterogeneous is smaller than that of pure ZnO and β-Ga₂O₃ according to the visible light absorption test. This demonstrates that the β-Ga₂O₃ coating cam expand the range of light absorption. Thus, the composite material showed excellent photoelectrochemical performance through the photocurrent test in the electrochemical workstation. The results indicate that β-Ga₂O₃@ZnO nanocomposite heterostructures have broad application potential in the field of optoelectronics.