Due to the excessive wear, the failure of U-shaped rings has become the main cause of wire breaking and dropping. Laser quenching is a green strengthening technology that can effectively improve the wear resistance of U-shaped rings. COMSOL Multiphysics is used to establish a simulation prediction model of temperature field and microstructure field for laser quenching U-shaped rings in this study. This model is used to investigate the influence of laser irradiation time on the distribution of temperature field and quenching field during the laser quenching U-shaped rings process. The model is verified by experimental comparison, and the simulation prediction results fit well with the experimental results. The simulation prediction results show that the temperature fields in the cross and longitudinal sections of the U-shaped rings′ center are crescent-shaped and diffuse into the inner U-ring with the increase of irradiation time. The surface layer of U-shaped rings after quenching is the fine quenched martensite structure. With the increase of depth, the microstructure in the heat affected zone is quenched martensite and a small amount of ferrite. The maximum temperature of U-shaped rings, the bottom depth and the surface area of the laser hardened zone are positively correlated with laser irradiation time. When the laser irradiation time is 7 s, the maximum temperature reaches 1 434 °C, the bottom depth reaches 3.12 mm, and the surface area reaches 817 mm2 covering 92.21 % of the upper surface area of the bending section of the U-shaped rings, which can effectively improve the wear resistance of U-shaped rings. Under the conditions of 5 000 W laser power and 24 mm×18 mm laser spot size, the laser quenching time window of U-shaped rings is 3~7 s.