Aiming at addressing the issue of the traditional metal damper's inadequate energy dissipation ca-pacity at low displacement levels and its inability to meet the energy consumption requirements of the structure at high displacement levels,a U-shaped metal tension-compression damper with two different sizes as energy dissipation components is proposed.This damper exhibits multi-stage yield and failure characteristics.Its bas-ic construction and restoring force model are given,and a finite element model of the damper is established u-sing Abaqus finite element software,with the mechanical properties of the damper being investigated through numerical simulations.The results show that the hysteresis curve of the damper is full with good energy dissi-pation and deformation capacity,and it can achieve the mechanical performance characteristics of multi-stage yielding,and its restoring force model is in good agreement with the simulation results.