The invention provides a circulating cooling system sewerage treatment method, including processes of electric flocculation-sedimentation, ultra-filtration and reverse osmosis. The method directs to the characteristic of chemical engineering equipment circulating cooling system sewerage, adopts electric flocculation pre-treatment and double-film treatment and coordinates ultra filtration effluentacidity adjustment process and reverse osmosis condensed water back washing process, and reverse osmosis producing water is close to water standard of first-class desalted water and can be directly recycled or subject to further desalination treatment. The treatment method has the characteristics of good treatment effect, stable operation, brief process and being economically feasible.