Abstract: A dynamic track irregularity calculation method based on acceleration integral algorithm is proposed. By eliminating the trend term and choosing a reasonable sampling ratio, the accuracy of displacement prediction by acceleration data is improved. A single wheel\|rail model introduced with track irregularity is established, and the obtained acceleration response of mass under the primary spring can reflect the dynamic track irregularity. Taking the metro vehicle of certain operation line as the research object, the influence of wheel tread on axle box vibration is investigated. The dynamic track irregularity prediction and comparison are carried out towards acceleration data of axle box on different lines, and the vehicle stability index on different lines is calculated. Research results show that the acceleration response of axle box can accurately reflect the characteristics of track irregularity. Therefore, the calculation method of dynamic irregularity based on axle box acceleration can provide a scientific basis for the daily maintenance of high-density lines. The fifth\|grade track irregularity PSD of U.S. railways is suggested for dynamic simulation of metro vehicles.