Microwave heating is an effective technique for inducing self-healing mechanism of asphalt mixtures in crack healing. This kind of asphalt mixtures usually contains metal additives to promote microwave heating. In order to explore the effect of different metal additives on the self-healing characteristics of asphalt mixtures, the microwave heating efficiency and crack healing ability of ordinary asphalt mixture without metal additives and asphalt mixtures with steel wool fiber, steel shavings or steel slag were compared in this study. The microwave heating efficiency of different mixtures was evaluated by the heating rate of different asphalt mixtures under the same heating time. Meanwhile, the crack healing ability was evaluated by the ratio of peak load of semi-circular bending test of asphalt mixtures before and after microwave heating. In addition, the rutting test, trabecular bending test, immersion Marshall test and freeze-thaw splitting test were carried out to evaluate the influence of different metal additives on the road performance of the respective asphalt mixture. The results showed that the microwave heating rate of the asphalt mixtures increased by 22.28%, 16.20% and 39.49% compared with normal asphalt mixture without additives, and the crack healing ability increased by 9.44%, 3.78% and 16.99% after adding steel wool fiber, steel shavings and steel slag, respectively. Therefore, the road performance of asphalt mixtures can be improved with varying degrees by adding these 3 metal additives.