Abstract: Electrolytic polishing of HRB600 hot rolled ribbed high-strength steel bar containing pearlitic structure was carried out in perchloric acid ethanol electrolytes containing different volume fractions (20%, 10%) of perchloric acid at different electrolytic voltages (20,15 V), and then nanoindentation test was carried out. The effect of electrolytic polishing conditions on the results of nanoindentation test was studied. The results show that the pearlite structure in steel bar after electrolytic polishing was dark brown and the ferrite structure was white. When the volume fraction of perchloric acid in the electrolyte was 20% and the electrolytic voltage was 20 V, the contrast difference between the two structures was relatively large, and the electrolytic corrosion degree was relatively large. Meanwhile, the average height difference between the cementation and ferrite in the pearlite was relatively large, that was, the surface roughness was large. The large surface roughness resulted in a plateau in the nanoindentation load-displacement curve, leading to distortion in the nanoindentation test. The recommended electrolytic polishing conditions were as follows: the volume fraction of perchloric acid in electrolyte was 10%, the electrolytic voltage was 15 V, the current was 3 A, the electrolytic time was 6 s, and the temperature was room temperature.