Abstract: Based on the measured rail profiles in metro curve section before and after grinding, a dynamic calculation model of real parameters is established for simulation. Combined with the field measured data, the grinding effect is quantified, and the result shows that the effective values of car body lateral and vertical vibration acceleration after the rail grinding are reduced by 7% and 2% respectively compared with the previous values, thus the smoothness of metro vehicles in curved section is improved. Meanwhile, the rail profile grinding can reduce the derailment coefficient by 5%—30%, the lateral creep force by 5%—40%, and the wear index by 10%—50%, thereby improving the safety of vehicle operation, reducing the incidence of rail surface diseases and wear rate. Field tracking observations show that the rail vertical wear rate in the grinding sections is 30%—40% lower than that in the non-grinding sections, indicating that the rail profile grinding can effectively reduce rail wear rate and prolong rail service life.