Based on similarity principles, this study proposes a reduced-scale modeling and testing method to investigate the dynamic responses of twin-bundle conductor lines after ice-shedding. The processes of ice-accretion and subsequent shedding on sub-conductors of bundled conductors were successfully simulated. A reduced-scale experimental platform was established to measure the in-plane, out-of-plane, and torsional motions of conductors after ice-shedding, as well as the time histories of conductor tension and the longitudinal, vertical, and horizontal components of reaction forces at the suspension points. Reduced-scale tests were conducted on a representative twin-bundle conductor line under three conditions: partial ice-shedding and unzipping ice-shedding from a single sub-conductor, and asynchronous ice-shedding between two sub-conductors. The variations in jumping height, lateral swing amplitude, torsion angle, and conductor tension, along with the reaction forces at suspension points over time, were recorded and analyzed.