The application relates to the technical field of wire tighteners, in particular to an insulating wire tightener and a fastening device, which comprises a wire bundle mechanism, the wire bundle mechanism comprises a wire tightener box, a shaft plate is fixedly connected to the right side of the inner wall of the wire tightener box, the shaft plate is provided with two and is fixed at the front end and the back end of the inner wall of the wire tightener box respectively, a wire winding column is fixedly connected to the inner side of the shaft plate, a steel
wire rope is arranged on the surface of the wire winding column, the steel
wire rope is wound on the surface of the wire winding column, and hooks are fixedly connected to the two ends of the steel
wire rope; the wire tightener is provided with a winding mechanism and a control mechanism, the control of the winding speed of the steel wire
rope and the
force balance of winding are realized, the stability and efficiency of operation are improved, the winding disc is locked in time after the winding action of the control mechanism is completed, the steel wire
rope cannot be completely tightened under the
high tension state through the force of the control mechanism, the locking state of the clamping mechanism is quickly released, the wire sliding rod is arranged to guide the steel wire
rope, and the safety and the convenience of operation are improved.