The excellent strain hardening behavior of high-manganese steel (HMnS) makes it widely used under strong impact and heavy wear conditions. However, the rapid hardening ability of HMnS needs to be improved under low stress. In this paper, laser remelting technology (LRT) was proposed to improve the hardening ability of HMnS under low stress. Firstly, the surface of HMnS was treated by LRT, and its surface and internal microstructure were characterized by a 3D profiler, an x-ray diffractometer, a scanning electron microscope (SEM) and an energy-dispersive spectrometer. Then, the microhardness and wear test were carried out by using a Vickers hardness tester and a wear tester, and the sub-surface microstructure and surface wear scars were tested by SEM and 3D profiler to study the wear performance of HMnS before and after laser remelting. Finally, the hardening effects and wear mechanism of laser-remelted high-manganese steel (LR-HMnS) were revealed. It was found that heterogeneities of LR-HMnS were composed of columnar structures, equiaxed structures and segregation region. These heterogeneities were conducive to improving the hardening ability of HMnS under low stress conditions, which could improve its wear resistance.