The invention discloses a method for cyclically degrading nitrobenzene in wastewater by utilizing extracellular polymeric substances to reinforce nano zero-valent iron. The method comprises the following steps of adjusting the pH value of the nitrobenzene-containing wastewater to 6.5-7.5, adding nano zero-valent iron and an extracellular polymeric substance, carrying out a stirring reaction, adding the nitrobenzene-containing wastewater again, adjusting the pH value to 6.5-7.5, adding the nano zero-valent iron and the extracellular polymeric substance, carrying out a stirring reaction, and rep...
