Chlorophenols (CPs) are widely used in the industrial production of wood preservatives, herbicides, fungicides, and pesticides. Because of its widespread existence and low biodegradability, CPs have caused harm to the environment, ecology and human health. In this study, we report a dechlorination system for the rapid degradation of p-chlorophenol (p-CP), in which hydroxylamine hydrochloride (HAH) promotes the activation of sodium percarbonate (SPC) with ferrous ions (Fe2+). The effect of the different parameters, including the pH, temperature, concentrations of percarbonate and inorganic anions (Cl-, SO42-, NO3-) on the degradation of p-CP was investigated. The results show that the degradation efficiency reached 99 % with a HAH: Fe2+: SPC: p-CP molar ratio of 5:5:5:1 at 20 °C for 5 min. The free radicals quenching experiments were performed to identify active species. The results show that p-CP is mainly degraded by hydroxyl radicals (HO·) in the dechlorination system. This dechlorination system showed excellent degradation performance for the chlorophenols, making it to be a potential oxidant for treatment of the contaminated water.