The utility model provides an external all alone reinforced structure includes at least that the diagonal bar restraints, turns to floor, support, steel sheet, horizontal muscle and restraint, turn to piece and anchor, turn to the piece set up the steel sheet lower extreme and with steel sheet zonulae occludens, the steel sheet setting is restrainted in the middle of horizontal muscle is restrainted and is turned to the piece and with horizontal muscle and is met, horizontal muscle is restrainted to set up and is being turned to the floor lower extreme and closely linking to each other, it sets up in diagonal bar bundle inboard to turn to the floor symmetry, the anchor setting is at diagonal bar bunchy top end and tighten close scarf joint with the diagonal bar, the diagonal bar restraint to be connected at the anchor with turn to between the piece and the lower extreme piece tightly connects with turning to, the support symmetry sets up and is turning to a both sides, this external all alone reinforced structure, construction convenience, save material reduces the cost, has reinforcements, unloads and reduce internal force's effect, can effectively improve the girder at the working property in normal use stage, and messenger fracture width narrows down, and the amount of deflection obviously reduces, has strengthened the durability of structure, is fit for using widely.