The utility model relates to a solar cell back sheet and subassembly thereof. The utility model discloses a solar cell back sheet, including the substrate layer with set up respectively in substrate layer two sides contain fluoride coat and modified polyolefin layer, the surface of substrate layer is through plasma activation and sculpture processing. The beneficial effects are that: the utility model discloses a solar cell back sheet has high weatherability, high wearing feature, separating nature of high resistant, and low cost, its aqueous vapor transmissivity are less than 1.0gm2. Day, compare in traditional solar cell back sheet, and its manufacturing cost can reduce more than 13%.