Abstract: Pilot-scale study was performed to investigate the hybrid PAC-UF process for settled water treatment in terms of validity and economic efficiency of it as a substitute of the conventional sand filter.The performance of the hybrid PAC-UF process was also compared with that of the conventional sand filter in the full-scale drinking water treatment plant and UF.Resultsshowed that,the hybrid PAC-UF process could ensure the biological-safety with(0.041±0.010) NTU and(13±8)/mL for the effluent of turbidity and particle number(particle size >2 μm).The process reduced influent COD_Mn and UV₂₅₄ by(21.0±9.9)% and(51.0±10.7)%,respectively.The process had a better performance for organic matter and turbidity removal compared with the conventional process,but it couldn't remove NH₄⁺-N effectively.The process could running stably under the experimental condition.The hybrid PAC-UF process was suitable for the raw water with high concentration organic matter and low concentration NH₄⁺-N.It could ensure the chemical-safety and biological-safety of effluent.