Abstract: An amino-functionalized nano Fe₃O₄@poly(styrene (St)-3-(2-amino tetraethylenepentamine)-2-hydroxypropyl methacrylate (HPMA)-divinylbenzene(DVB)) (Fe₃O₄@P(St-HPMA-DVB)) magnetic composite was synthesized via ultrasonic assisted suspension polymerization and applied for adsorption of Cr(Ⅵ) in aqueous. The post-absorbed Fe₃O₄@P(St-HPMA-DVB)-Cr(Ⅵ) magnetic composite was collected and characterized by TEM, vibrating sample magnetometer (VSM), TGA, XRD, elemental analysis (EA) and FTIR. The application for its catalytic properties as the heterogeneous catalyst for the degradation of 2,4,6-trichlorophenol(2,4,6-TCP) was investigated. The results show that when loading amount of Cr(Ⅵ) at 200 mg/g on the Fe₃O₄@P(St-HPMA-DVB)-Cr(Ⅵ), the solution pH value at 3.0-4.5, and H₂O₂ concentration above 4.08 mmol/L, the degradation of 2,4,6-TCP with initial concentration less than 20.0 mg/L (101.3 μmol/L) can be achieved nearly 100% within 10 min by the Fe₃O₄@P(St-HPMA-DVB)-Cr(Ⅵ)/H₂O₂ system. Fe₃O₄@P(St-HPMA-DVB)-Cr(Ⅵ) can be reused after recycling for 5 times, with degradation percentage of 2,4,6-TCP still remaining over 95%.