The invention relates to a copper-indium-gallium-selenium film photovoltaic cell device and a preparation method thereof. The copper-indium-gallium-selenium film photovoltaic cell device comprises a substrate, a back electrode layer, a copper-indium-gallium-selenium photoabsorption layer, a buffering layer, a blocking layer, a conducting window layer and a grid electrode, which are sequentially overlapped with each other, wherein the grid electrode is a p type or n type graphene film. The nearly transparent graphene film is utilized as the grid electrode of a CIGS film photovoltaic cell device, the most remarkable advantage thereof is light transmission, and a single layer of graphene only absorbs 2.3% of light, and the graphene is completely light tight compared with the commonly utilized Ni/Al grid electrode, so that the effective light acceptance area of the photovoltaic cell device is increased, the short circuit current is raised and the cell efficiency is improved as well.