Abstract: The investigation and analysis on the wastewater discharged from one large corn deep processing company were performed. It showed that the wastewater had high concentrations of organic matter, SS and chloride. Biological aerated filter (BAF) and membrane bio-reactor (MBR) were adopted to perform deep treatment for the wastewater from the total discharge outlet as well as from the IC reactor outlet. Both processes showed favorable wastewater treatment efficiency except for chloride removal. The rotary coupon method combined with scanning electron microscopy was used to perform corrosion test for the effluent from the lab-scale deep treatment facilities, to investigate the feasibilities of the effluents as supplementary water for circulated cooling system directly. The results indicate that the effluent from BAF and MBR cannot be used as supplementary water directly according to the conspicuous acceleration of chloride on corrosion process. Reverse osmosis could not only reduce chloride concentration to less than 0.5 μg/L, but also could meet requirements to reuse for circulated cooling system. Compared with the operational cost of the company, the reuse of the effluent from reverse osmosis process as supplementary water for circulated cooling system can save the cost and gain certain economic benefit.