Para-chloronitrobenzene degradation by Fenton-like with zero-valent iron and hydrogen peroxide was studied in depth for the purpose to solve the circulation of iron ions suffocated caused by the slow rate of Fe³⁺ returns Fe²⁺ in the traditional Fenton reaction. Different effects of hydrogen peroxide and iron dose, initial pH value and others factors were investigated. Para-chloronitrobenzene removal efficiency of 73％ was achieved under optimal reaction conditions of pH value 5, with dosage of 200 mg／L zero-valent iron, and 3.5 mg／L of hydrogen peroxide after 20 min. The Removal efficiency of para-chloronitrobenzene by Fe⁰／H₂O₂ Fenton-like increased 20％-30％ than the traditional Fenton reaction under the same dosage of iron and hydrogen peroxide, and the same of pH value. And in 3-7 range of the pH value, para-chrornitrobenzene degradation effects were obvious by Fe⁰／H₂O₂ Fenton-like. The choro-(—Cl) and nitro-(—NO₂) on the phenyl were transformed inorganic ions incomplete. The main intermediates were oxalic acid, glycolic acid, acetic acid, maleic acid, p-nitrophenol, p-chlorophenol, 2-chloro-5-nitrophenol, 5-chloro-2-nitrophenol. An degradation pathway of the para-chloronitrobenzene was also proposed.