To address the technical difficulties associated with the replacement process of group-anchored steel strand cables for long-span cable-stayed bridges, such as the lack of force-release structures in the anchorages, large elongation, and difficulty in single-strand unloading, this paper takes the cable replacement project of the Yiling Yangtze River Bridge as the background and proposes an integrated cable force release device and construction technology suitable for long-cable replacement. The device connects the replacement anchorages with the exposed steel strands of the old cables and combines reaction support frame, tensioning rod, and jacking system to achieve graded and synchronous unloading of cable force, effectively addressing the limitations of the original anchorages, which cannot directly release cable force and have insufficient adjustment capacity. Engineering practices shown that this method ensures safe and controllable construction, smooth cable force unloading, and minimal structural disturbance, successfully achieving the replacement of all 236 stay cables on the bridge. Post-construction inspection confirms that the cable forces and deck alignment meet the design requirements, verifying the reliability of this technology. The technical system described in this paper can provide references for the design and construction of cable replacement in similar bridges.