Three-dimensional-electrode electro-Fenton reactor, which activates carbon and coated carbon as filled electrode, was employed to treat landfill leachate. Impact factors and treatment efficiency were studied. Experimental results showed that the optimal operating conditions were as follows: current density 57.1 mA/cm2, airflow 0.2 m3/h, dosage of Fe(II) 1.0 mmol/L, initial pH 4.0. Under these conditions, the removal rates of COD, ammonia-nitrogen and TOC were up to 80.8%, 55.2% and 98.6%, and the value of BOD5/COD was improved from 0.125 to 0.486 within 180 min of electrochemical oxidation. Analytical results of GC-MS indicate that the organic compounds such as aromatic hydrocarbon, alkane, carboxylic acid and ester are well degraded by three-dimensional-electrode electro-Fenton process which is proved to be an effective way to treat landfill leachate.