In this paper, combination of multi-stage biological contact oxidation (MBCO) and single-stage autotrophic nitrogen removal using anammox and partial nitrification (SNAP) was used to treat high concentration of chemical oxygen demand (COD) and ammonia nitrogen in landfill leachate. MBCO was optimized using response surface methodology (RSM), achieving 91.3% COD removal efficiency. For ammonium nitrogen, nitrogen removal rate (NRR) of 1.68 kg N/m(3)/d was obtained in 140 days. Since MBCO effluent contained 350 mg/L COD, bio-oxidized humic acid was used as the stimulant COD source in SNAP influent. As a result, refractory COD almost had no impact on nitrogen removal ability of SNAP reactor and 20% COD was removed. Besides, the bacteria community structure analysis also demonstrated that the bio-oxidized humic acid didn't change the bacterium proportion obviously. This new combination provided landfill leachate treatment with an effective alternative.