The utility model discloses a bare grounding flat iron sheath. The sheath comprises a semicircle sphere sheath of an upper portion and a cylinder sheath of a lower portion. The semicircle sphere sheath comprises a transparent plastic hemispheroid, a liquid filling rubber capsule and an outermost layer of translucent rubber protection layer. The transparent plastic hemispheroid is located at a center position. The liquid filling rubber capsule is located between the transparent plastic hemispheroid and the translucent rubber protection layer. The cylinder sheath is a hollow structure. An internal hollow structure shape and a height are matched with a shape and a height of the bare grounding flat iron. The semicircle sphere sheath and the cylinder sheath form one-body structure. An outer surface of the semicircle sphere sheath is provided with two circles of fluorescent strips. The sheath of the utility model can be directly placed on an end portion of the bare grounding flat iron and can be installed on a bare steel bar fracture of a construction site according to a need so that on-site working personnel can be prevented from being damaged by the flat iron fracture. Even if there is bump, because of an elastic shell design, an outer force is greatly buffered and a safety coefficient of the working personnel is increased.