Abstract: The effects of an antibacterial agent dodecyldimethylbenzylammonium chloride (1227) and electromagnetic treatment on microbial corrosion of stainless steel in simulated cooling water containing sulfate reducing bacteria (SRB) were studied through electrochemical testing and surface analysis. The results show that the antibacterial agent 1227 had good antibacterial performance, with a 100% inhibition rate at a mass concentration of 20 mg/L. After adding antibacterial agent 1227, the impedance modulus of the stainless steel significantly increased, and the passive current density significantly decreased. The antibacterial agent could play a good role in inhibiting microbial corrosion. The antibacterial effect of electromagnetic treatment on SRB was poor, with a maximum antibacterial rate of 42.46%, but its inhibitory effect on microbial corrosion was equivalent to that of antibacterial agent 1227. When the simulated cooling water solution was treated with antibacterial agent 1227 or electromagnetic treatment, the surface biofilm adhesion of stainless steel immersed in it was significantly reduced.