The invention belongs to the technical field of photovoltaic modules, and particularly relates to a low-acid white EVA photovoltaic packaging adhesive film and a preparation method thereof.The low-acid white EVA photovoltaic packaging adhesive film is prepared from 100 parts of EVA resin, 5-10 parts of titanium dioxide, 1-5 parts of a composite acid inhibitor, 0.5-1.0 part of a peroxide cross-linking agent, 0.3-1.0 part of an assistant cross-linking agent, 0.2-0.6 part of a coupling agent, 0.1-0.5 part of an antioxidant and 0-0.5 part of an ultraviolet absorbent, the composite acid inhibitor is prepared by mixing an amphiphilic polymer, an alkaline metal compound, a carbodiimide compound and a macromolecular coupling agent in proportion and granulating. According to the low-acid white EVA photovoltaic packaging adhesive film disclosed by the invention, the composite acid inhibitor is added, so that not only can the power loss of a component caused by water vapor erosion be solved, but also free acetic acid generated in the long-term aging process of EVA can be effectively neutralized, the corrosion of the packaging adhesive film to a battery piece, a bus bar and a metal frame is effectively relieved, and the service life of the component is prolonged.