The invention relates to a method for realizing autoloader on an exposure roller and a device thereof. The device comprises a front plate clamp and a tail plate clamp that are used for clamping and fixing a printing plate on the exposure roller, a clamp opening device which is used for controlling opening/closing of the front plate clamp and the tail plate clamp respectively, a positioning plate delivering device which is used for positioning the printing plate and delivering the printing plate to the appointed position, and a holding device which is used for holding the printing plate at thepositioning plate delivering device and respectively delivering the front edge and the back edge of the printing plate in the front plate clamp and the tail plate clamp that are opened by controllingby the clamp opening device, so as to realize automatic plate loading, and the holding device is also used for holding the back edge of the printing plate on the exposure roller and pulling the printing plate out of the tail plate clamp and the front plate clamp, so as to realize automatic plate unloading. By adopting the method and the device, the plate clamp is unnecessary to open in a large angle, the operation processes of the plate loading and plate unloading for the exposure roller can be realized automatically and more conveniently in the plate making process.