Abstract: The corrosion behavior of 10 steel in simulated circulating cooling water containing different contents of SS317NC bactericide(90-170 mg·L-1)was studied by polarization curve test, scanning electron microscope, energy spectrum analysis and weight loss method, and the effects of SS317NC bactericide contents on the corrosion behavior were analyzed. The results show that under the combined action of sulfate-reducing bacteria (SRB), iron oxidizing bacteria (IOB) and corrosive anions, with the increase of SS317NC bactericide content the corrosion tendency and corrosion rate first decreased then increased, and achieved the minimum value when the bactericide content was 130 mg·L-1. The corrosion tendency and corrosion rate of 10 steel in simulated solution containing SS317NC bactericide were less than in those without bactericide. General corrosion was observed on the surface of 10 steel and there was no activation-passive transition zone. The corrosion products were composed mainly of iron oxides and few sulphides. SS317NC bactericide can effectively improve the corrosion resistance of 10 steel.