The invention discloses a knittable full-carbon memory storage device, a preparation method therefor, and an application. The storage device comprises carbon nano tube fibers wrapped by acidic thermal reduction graphene, and an electrode. The preparation method comprises the steps: taking oxidized graphene as a raw material, forming acidic oxidized graphene aqueous solution through adjusting a pH value, wrapping the surfaces of flexible carbon nano tube fibers with the oxidized graphene through employing a method of solution immersion, carrying out the reduction of the oxidized graphene through thermal treatment, weaving the obtained functional carbon nano tube fibers in an intersected manner, connecting an upper electrode, and forming the storage device. The storage device provided by the invention is high in switch ratio, is high in switching speed, is long in switch service life, is good in flexibility, is easy to machine and form various types of braided fabrics, is especially suitable to serve as wearable electronic equipment, and is simple in manufacturing technology. The raw material is easy to obtain, and the device is simple. Moreover, the device is low in cost, and is suitable for large-scale production.