Abstract: The effect of different cold rolling reduction rates (15%-55%) on the microstructure and properties of ZGMn18Cr2 steel was studied by means of microstructure observation, XRD, hardness test and impact wear test.The results show that ZGMn18Cr2 steel treated with water toughening at 1120℃×2 h has uniform austenitic structure and equiaxed grains.With the increase of cold rolling reduction rate, the grain of the steel is constantly elongated along the rolling direction, and the deformation zone is gradually increased, the dislocation density is gradually increased, and the hardness and wear resistance of the steel are gradually increased.Compared with those of ZGMn18Cr2 steel without cold rolling, the hardness of the steel with cold rolling reduction rate of 55%is increased by 131.5%, and the mass loss of impact grinding is decreased by 37.3%.