The invention provides a cambered bottom electrode thin film solar cell comprising metal top electrodes, a transparent conductive thin film, a P type amorphous silicon thin film, an intrinsic amorphous silicon thin film, an N type amorphous silicon thin film, a metal bottom electrode and a substrate, which are connected in sequence from top to bottom, wherein a plurality of conductive metal flanges are arranged on the upper surface of the metal bottom electrode, the N type amorphous silicon thin film, the intrinsic amorphous silicon thin film, the P type amorphous silicon thin film and the transparent conductive thin film above the flanges are provided with upward protruding strip-shaped bulges, the metal top electrodes are arranged at the two sides of the strip-shaped bulge of the transparent conductive thin film. According to the cell provided by the invention, the bottom electrode is provided with cambered or approximate cambered flanges, and the flanges stretch into the thin films to improve the current collection ability of the electrode; the successively deposited thin film material on the bottom electrode forms cambered bulges at positions corresponding to the flanges to increase the area of the thin film cell and increase the illuminated face of the cell; and the bulges of the thin film form a convex lens to collect the incident light so as to improve the light absorption and utilization of the cell, thereby further improving the conversion efficiency of the cell.