Abstract: The flash welded joint of U75V steel rail was grinded with a self-designed rail grinding and friction testing machine at different grinding rotation speeds （1 000, 2 000, 3 000 r·min⁻¹）, and the influence law of grinding rotation speed on the material removal behavior of the weld and base metal of the rail welded joint was studied. The results show that as the grinding rotation speed increased, the grinding temperature of the rail welded joint increased from 80 ℃ to 140 ℃, and both the friction coefficient and grinding volume first decreased and then increased; the surface roughness of the weld first decreased and then increased, but that of the base metal first increased and then decreased; the damage mechanism of the weld transitioned from cutting to a combined cutting/spalling mode, and the thickness of the hard and brittle white layer formed on the surface increased significantly. At a grinding rotation speed of 3 000 r·min⁻¹, the thickness of the white layer on the surface of the weld reached approximately 320 μm. With increasing grinding rotation speed, the damage mechanism of the base metal shifted from cutting to material plastic flow, and almost no white layer was observed on the surface. Compared with the base metal, the weld experienced more severe damage, and had a greater oxidation degree at higher grinding rotation speeds （2 000, 3 000 r·min⁻¹）.