The present invention discloses a double-row cable tightening device, comprising multiple adjusting components, both ends of the multiple adjusting components are fixedly connected with clamping components, fastening components are slidably installed on both sides of the adjusting components, the interior of the fastening components is sleeved with double-row cables, and the multiple adjusting components are mutually embedded and installed through the clamping components. In the above scheme, one end of the double-row cable can be connected to different positions, and the double-row cables can be tightened to make the overall structure more neat and beautiful. The multiple tightening devices can be mutually clamped to complete the fixation, so that the multiple double-row cables are tightened to each other, the connection is flexible and neat, and the later maintenance and inspection are convenient. At the same time, when the sleeve is sleeved on the outer surface of the double-row cable, the sleeve will be deformed and wrapped around the outer surface of the double-row cable, which can not only fix the double-row cables of different diameters, but also prevent the double-row cables from being squeezed and deformed, or the surface from being worn, thereby avoiding reducing the service life of the double-row cables.