The invention discloses a hydrolytic acidification reactor for a sewage plant in an industrial zone, relates to a hydrolytic acidification reactor, and aims to solve the problems of poor wastewater biodegradability and poor water quality and volume fluctuation of an existing industrial zone. The hydrolytic acidification reactor is divided into five compartments by partition walls, wherein a sludge pit is arranged at the bottom of the first compartment; a deflection baffle is vertically arranged in each of the second compartment, the third compartment, the fourth compartment and the fifth compartment; the second compartment is divided into a downwelling region and an upwelling region by the deflection baffle; an elastic filler is arranged in the upwelling region of the second compartment in a hanging manner; a dredge pipe and an aerator pipe are arranged at the bottom of the second compartment; the structures of the third compartment, the fourth compartment and the fifth compartment are the same as that of the second compartment; the density of an elastic filler in the fifth compartment is higher than the density of the elastic filler in the second compartment. According to the hydrolytic acidification reactor, the hydraulic flow state is optimized by deflection baffle structures, loss of sludge is reduced by the high-density filler in the last compartment, and a hydrolytic acidification effect is improved.