The invention discloses a processing method for thin-wall barrels. The method comprises the steps such as setting-out, blanking, circle-shearing, milling processing, wrapping, welding, welding seam grinding, stretching and forming, explosive forming and the like. The processing method is simple and convenient to operate, a plurality of thermal-treatment tempering processes are not needed, processing steps are simplified, and time consumption is reduced, so that the processing efficiency is improved; the processed thin-wall barrels are high in dimension consistency and are high in precision, so that the production cost can be reduced; besides, the processing method further has relatively wide applicability, and can be used for processing other similar thin-wall barrels.