The invention discloses an open strapped-down tightener, which comprises a handle, a steel U-shaped ring fixed on the handle and a tie strip, wherein one end of the tie strip surrounds the steel U-shaped ring and the other end passes through the steel U-shaped ring; the tie strip is in an open form and the size can be adjusted according to the requirements of to-be-tightened articles; the application range is very wide; the open strapped-down tightener is suitable for installation and removal of various tightening fittings of a 500kV and above power transmission line, installation and removal of various spacers, and repairing operations of repairing treatment of loose and separate guide wires, tightening and binding of excess wires of optical cables, pre-twisted accessory installation assist and the like; the open strapped-down tightener is simple in structure, few in used materials, low in manufacturing cost, economical and practical; the safety coefficient of line operation is improved by the research achievement; the working time is shortened; and the working strength is reduced.