Abstract: The effects of different cooling methods on the microstructure and properties of rare earth heavy rail steel U75V were analyzed by Zeiss optical microscope, scanning electron microscope, microhardness tester, MTS universal testing machine and other experimental instruments. After 850 ℃insulation for 15 min, and the heavy rail steel samples with different sheet spacing were prepared with furnace cold, air cooling and air cooling respectively, with the average lamella spacing of 514 nm, 245 nm,142 nm, respectively. The results show that the average grain size, spacing of bead sheet layer, hardness,tensile strength and postfracture elongation are obviously different. The average grain size of heavy rail steel cooled with the furnace is the maximum, with the minimum is 8.51 μm, hardness is 293.2 HV, and poor mechanical properties. After tempering, the air-cooled heavy rail steel has the highest tensile strength（1124.5 MPa） and the impact energy is 35.5 J.Compared with other cooling methods, its tensile fracture surface is more smooth, and deep cracks and holes disappear, and the obvious dimples appear.