The utility model provides a cable straining device, including fixed plate, belt tightener, install the support frame on the fixed plate, be equipped with rotatable ratchet on the support frame, the belt tightener is fixed in one side of ratchet and is set up with the ratchet is concentric, is equipped with on the belt tightener that the card is traditional thread binding to be put, still be equipped with the control rocking handle on the support frame, rear end upper portion is equipped with supplementary seat on the fixed plate, be equipped with convex spout on the supplementary seat, the other end of control rocking handle is installed servo axis and is held, servo axis hold the setting in the spout and with spout sliding fit, fixed plate front end upper portion is provided with guider. This cable straining device simple structure, it is nimble convenient to use, labour saving and time saving, easy?job personnel's electric power?construction operation greatly.