In order to conduct deep treatment of low concentration petrochemical wastewater, a novel type of polystyrene (PS) microsphere adsorption resin was synthesized by emulsion polymerization of styrene, butyl acrylate and polymerizable quaternary ammonium salt by emulsion polymerization.The resin was characterized by IR,SEM and BET,and compared with several commercially available adsorption resins D301,XAD⁃4 and NDA⁃150.The results show that the synthetic resin has an irregular spherical shape with a diameter of 0.2~0.4 mm,and the COD of the petrochemical secondary wastewater can be reduced from 100 mg/L to below 20 mg/L within 24 h.The adsorption behavior of this resin on petrochemical wastewater is close to that of monolayer,and the saturated adsorption amount reaches 89 mg/g,which was higher than the commercially available resins D301 (85.5 mg/g),NDA⁃150 (30.4 mg/g) and XAD⁃4 (58.8 mg/g).Ozone oxidation regeneration results show that the synthesized PS resin can be recycled more than 4 times,which has better regeneration performance than other conventional adsorption resins. This material can be used as an excellent adsorbent for treating petrochemical wastewater in advanced treatment processes for low⁃concentration wastewater.