A new amorphous silicon film solar cell structure is designed, where the antireflective coating consists of double layer gratings. The Si film is etched into the array of Fresnel zone plate (nonperiodic grating) structure to focus light to the amorphous silicon film and amount of Si can be saved. The indum tin otide (ITO) film on Si is etched into a subwavelength and nonperiodic grating array. The designed double grating antireflective film can reduce refraction and increase the broadband transmission of light. The intensity distribution of reflection and transmission fields are simulated by using the finite difference time domain (FDTD) method. The simulation results show that, compared with the conventional amorphous silicon film solar cell without grating antireflective film, the absorptivity of light and the short-circuit photocurrent density can be improved by 19.9% and 19.9%, respectively. These results are better than results of the reported solar cell with an antireflective film of double layer periodic gratings and a metal grating back electrode.