Abstract: A high efficient hydrolysis and acidification process for wastewater pretreatment was demonstrated in this study,through the analysis of the limitation of present hydrolysis and acidification processes used in many wastewater treatment plant.The novel process included suspending activated sludge phase,solid-liquid separation phase,biofilm phase,and the wastewater was treated by three phases in sequence.Through the treatment of the synthesis beery wastewater,when theρ(COD)of influent was 0.6~1.0 g/L,more than 50% ofρ(COD),70% ofρ(SS)removals were achieved under a HRT of 3.5 h,andρ(BOD₅)/ρ(COD)of effluent was increased by 25%.At the same time,the effect factors of MLSS in suspense phase,HRT and the organic load of influent for the nutrient removal and the sludge reduction in suspense phase were studied. In conclusion,the novel process has some merits:high endurance of the impact from the influent organic loading,excess sludge could be reduced effectively by the hydrolysis and acidification process,high efficiency of hydrolysis and acidification,occupancy land area is minor,and apt to unify construction and management.