An exposure device, an exposure method and a photolithography method are provided. The exposure device includes an exposure light source and an optical-path assembly, the optical-path assembly is configured to guide light emitted by the exposure light source to an exposing position, the optical-path assembly includes a light valve array, the light emitted by the exposure light source is able to be guided to the light valve array and then guided to the exposing position after the light is transmitted or reflected by the light valve array, the light valve array includes a plurality of light valve units, and optical transmittance or reflectivity of each of the light valve units is adjustable.