Abstract: To solve the deficiency of the current evaluation index and realize the optimization of anti-rutting of asphalt mixtures, based on the urban road repair project, this paper adopted the discrete element and plastic activation energy (E_a) evaluation method to optimize the anti-rutting performance of the test road from gradation design. The theory of plastic activation energy was emphatically introduced, and the test and calculation method of E_a were given. During the research process, the optimized gradation was first determined through the virtual creep test of discrete element, then the indoor creep tests were carried out on the asphalt mixture with the optimized and original gradation, including the tests under the conditions of immersion and non immersion, 20 ℃ and 40 ℃, damage (300 kPa) and non-damage (25 kPa), respectively. At the same time, the E_a was calculated based on the theory, and the results show that the optimal gradation has higher value of E_a. Finally, the asphalt mixture with the original gradation and the optimized gradation were used to build the test road, and the settlements were monitored. The results show that the rutting of the road with the optimized gradation is smaller, which is consistent with the evaluation results of the E_a.