The invention relates to a high-concentration high-acidity waste water treatment method of an N-phenylmaleimide one-step synthesis technology. The method is characterized in that reaction water produced by a reaction process and all waste water produced by water washing and neutralization processes in post-treatment are recovered and recycled so that the whole process does not produce waste water. The treatment method comprises carrying out vacuum filtration on washing water and neutralization water, mixing the filtrate and reaction water, adding an organic solvent into the mixture, carrying out azeotropic distillation, utilizing all the distillated water as next-batch reaction washing water, utilizing the washed filter residues for a synthesis reaction to obtain a high-quality product with content of about 98.4%, mixing the distillation residues and washing and neutralization residues, and burning the mixture as industrial garbage at a high temperature so that 90% of solids are removed and only about 10% of solid wastes are retained. The method has simple processes, realizes a low cost, does not produce waste water, is suitable for industrial production and is environmentally friendly.