The invention discloses a solar external sunshade device, comprising a metal barrel, vertically-arranged metal groove strips are welded at the two ends of the side wall of the metal barrel, the two metal groove strips are tangent to the cylindrical surface of the metal barrel, one ends of the two metal groove strips are welded with the same transverse strip, an electric roller is fixed to the inner wall of the metal barrel through bolts, a sunshade curtain is wound around the side wall of the electric roller, a rectangular hole is formed in the side wall of the metal barrel, sliding blocks arearranged on the inner walls of the two metal groove strips in a sliding mode, the same metal strip is fixed to the side walls of the two sliding blocks through bolts, and one end of the sunshade curtain penetrates through the rectangular hole and is clamped to one side of the side wall of the metal strip. According to the solar external sunshade device, the metal strips can conveniently move in the directions of the metal groove strips, the sunshade curtain can be conveniently rolled and unfolded, dust on the surface of the sunshade curtain can be conveniently scraped off through a brush strip, the cleaning and maintaining difficulty is reduced, and the power generation efficiency of an arc-shaped solar power generation panel is guaranteed.