ObjectiveTo investigate the effect of new comprehensive treatment scheme on the treatment of central airconditioning circulating water, and compared with the original treatment scheme, so as to take more effective measures to prevent and control the source of healthcareassociated infection.MethodsAfter the implementation of two water treatment schemes, biofilm dynamic trend, microorganisms, and corrosion rate were detected by online microbial analyzer and biofilm detection kit. ResultsAfter the implementation of original scheme, biofilm trend value of central airconditioning circulating water was continuously high, maintaining at 200-500; pathogens (Pseudomonas aeruginosa) existed in the circulating cooling water; corrosion testing showed that corrosion coupons were severely corroded. After the implementation of new scheme, biofilm trend value declined continuously, and finally stably maintained below 20; pathogens were not detected after 6 days, which was corresponded to biofilm trend value; corrosion coupons were slightly corroded，corrosion rate was＜0.075 mm/a. ConclusionNew comprehensive treatment scheme is definitely effective for reducing and controlling the growth of pathogens, biofilm and corrosion.