Abstract: By means of microstructural observation, tensile test, immersion test and electrochemical test, the effects of spheroidizing treatment on the mechanical properties and corrosion behavior of pearlite steel in an acidic chloride ion environment were systematically studied. The results show that cementite phase was the core factor regulating the mechanical properties of pearlite steel, and the strength loss caused by its morphological transformation was the dominant reason for the decrease in steel strength after spheroidizion treatment. The micro-galvanic corrosion effect between cementite and ferrite was the key factor determining the long-term corrosion resistance of pearlite steel. Compared with the as-received steel, the amount of cementite accumulation on the surface of spheroidized steel was significantly reduced, and the microgalvanic effect was obviously weakened, thus exhibiting more excellent long-term corrosion resistance.