The removal effect of Fenton oxidation, flocculation precipitation and Fenton-flocculation combined treatment process on organic matter, NH3-N and TN in aged landfill leachate is studied, and the process conditions are optimized. The results show that the Fenton-flocculation combined treatment process with Fenton oxidation and then flocculation precipitation has the highest removal rate for CODCr and TOC in the aged landfill leachate. When the dosage of FeSO4 is 0.015mol.L^-1, the ratio of [H2O2] / [FeSO4] is 1.5, and the dosage of PAC is 4 mL, the removal rates of CODCr and TOC can reach 90.2% and 90.7%, respectively.