The invention discloses a wastewater treatment method of a para-ester acetanilide route, and belongs to the field of para-ester wastewater treatment. The method is used for treating chlorosulfonated wastewater, and comprises the following steps: concentrating the chlorosulfonated wastewater: dripping the chlorosulfonated wastewater from the top of an evaporation pipeline through a plurality of droppers, arranging a plurality of heating rings on the evaporation pipeline side by side from top to bottom, controlling the heating temperature of the heating rings to be 95 to 120 DEG C, performing air exhaust at the top end of the evaporation pipeline to maintain the pressure intensity in the evaporation pipeline to be 0.6 to 0.8 atm, collecting liquid dripped into the bottom of the evaporation pipeline to obtain a wastewater concentrate, and reacting the wastewater concentrate with aniline to obtain p-aminobenzenesulfonic acid. The process is simple, the treatment efficiency is high, and resources are comprehensively utilized.