Abstract: This paper develops a new rotation-magnified viscoelastic damper, and the leverage principle is used to magnify the relatively small rotation angle at the beam-column joint of a structure. By magnifying the rotation angle, the energy dissipation capacity of the damper is fully utilized to achieve a more ideal vibration control effect. First, the basic structure and working principle of the damper are introduced, and a physical model is manufactured. Then the frequency dependency, deformation dependency and fatigue performance loading tests of the damper have been performed to investigate the change law of its mechanical performance indexes, such as the maximum damping force, equivalent shear stiffness, energy consumption per cycle and equivalent viscous damping ratio. Finally, the mechanical properties of the traditional angle damper without amplification function are tested to validate the energy consumption amplification ability of the proposed damper. Results show that: the hysteresis curve of the damper is plump with stable hysteresis performance, and the anti-fatigue performance is good; compared with traditional angle damper without amplification function, its energy consumption capacity can be increased by up to 4.42 times.