The invention provides a method for installing a three-stage vibration-isolation energy-dissipation support for a bridge. Three-stage energy dissipation is formed by setting upper energy consumption,middle energy consumption and lower energy consumption, and the vibration reduction effect is improved. Sliding surfaces of the sine and cosine surfaces are disposed in an upper energy-dissipation vibration-reduction structure and a lower energy-dissipation vibration-reduction mechanism respectively, the cooperation of the sine and cosine surfaces is achieved, and the range and work performance ofthe damping effect are improved. A restraining spring and a carbon fiber cloth are arranged on a U-shaped energy-consuming metal plate, to restrain displacement of the U-shaped energy-consuming metalplate, so that the deformation capability of the U-shaped energy-consuming metal plate is improved, and the adaptability of the support to earthquake and vibration displacement is enhanced.