The invention relates to an outer protecting type copper water stop structure and an outer protecting method thereof. The outer protecting type copper water stop structure comprises a water stop copper piece which is integrally formed by two copper piece bodies, and a wrapping body wrapping the outer side of the water stop copper piece. The outer protecting method includes the steps that the interior of the water stop copper piece is filled with and closed by foam materials; the wrapping body closely wraps the water stop copper piece; and after the outer protecting type copper water stop structure strides over a seam to be in place, concrete components on the two sides are poured successively, and a reserved telescopic seam is formed between the concrete components on the two sides. According to the outer protecting type copper water stop structure and the outer protecting method of the outer protecting type copper water stop structure, due to the fact that the wrapping body is arranged on the outer side of the water stop copper piece, a space in which the water stop copper piece can conveniently stretch and deform is formed in the outer side of the water stop copper piece, the deformation restraint of the water stop copper piece can be remarkably reduced, the water stop copper piece can fully stretch and deform according to the expectation of a designing party when the expanding, settling and/or shearing three-direction position change happens to the telescopic seam, and the water stop reliability of the copper water stop structure is remarkably improved.