The utility model discloses a protective cap design steel mould, including two steel calligraphy or painting models body, every steel calligraphy or painting model body is connected gradually by 3 blocks of facade steel sheets that to be the open -ended trapezoidal, the outside weld edgewise on the vertical side edge of the facade steel sheet of two steel calligraphy or painting model body opening parts has the connecting plate, and two steel calligraphy or painting model body openings are connected for six positive prisms through the connecting plate relatively, and the junction of two steel calligraphy or painting model bodies is connected through the hasp, the seam crossing of two steel calligraphy or painting model bodies is provided with the self -adhesion rubber pad, the inside of the top of of facade steel sheet has the copper wire strip along the flange welding, the top and bottom along the competent steel sheet of flange welding in the facade steel sheet outside. The utility model discloses but simple structure batch production is adapted to more engineering, practices thrift the manpower financial resources. The utility model discloses the back is pour in the installation, and is from the band wire strip during protective cap shaping, very pleasing to the eye. The utility model discloses dismantle simply, little to the influence of protective cap quality during the dismantlement, washing and maintenance are simple, and reuse rate is high.