The invention relates to the field of hygienic products. A disposable adult paper diaper comprises a cover, an absorption body, hook & loop fasteners, leakproof retaining walls and leg portion elastic rubber bands. The absorption body is arranged in the cover, and the hook & loop fasteners, the leakproof retaining walls and the leg portion elastic rubber bands are arranged on the cover. A non-water penetration external layer is composed of a middle portion and two external portions at two sides. Two hook & loop fasteners are arranged at each end in parallel in the length direction, and a gap is disposed between the two hook & loop fasteners. The absorption body is provided with guiding gutters, and the absorption body is divided in to a middle area, connecting areas and side areas in the width direction. The disposable adult paper diaper is low in production cost, good in comfort during usage, good in leakproof effect at side portions, and liquid hardly penetrates the crotch portion.