The invention discloses a solar cell back panel film and a preparation method thereof. The solar cell back panel film is prepared from the following raw materials in parts by weight: 12 to 20 parts of butyl rubber, 20 to 32 parts of polyvinylidene fluoride PVDF, 4 to 10 parts of dipropylene glycol, 12 to 24 parts of polyester glue powder, 2 to 8 parts of sodium polyacrylate, 4 to 10 parts of benzalkonium chloride, 20 to 30 parts of polystyrolsulfon acid, 8 to 14 parts of silicon dioxide, 6 to 10 parts of polyetherimide, 2 to 8 parts of 2,6-ditert-butyl-4-methylphenol, 6 to 12 parts of sodium carboxymethylcellulose, 1 to 7 parts of polytrimethyl dihydroquinoline, 0.2 to 0.8 part of dilauryl thiodipropionate, 1 to 5 parts of hindered amine light stabilizer and 0.6 to 1.8 parts of dioctyl phthalate. According to the solar cell back panel film disclosed by the invention, the service life of a solar back panel can be effectively prolonged, the heat resistance, ageing resistance, vapor permeability resistance of the solar back panel are strengthened, the solar cell back panel film has relatively high breakdown voltage performance and can be completely adhered with a base material together, and the solar cell back panel film is not easy to peel off and is wide in application prospect.