The invention relates to a technology for treating sewage of livestock-poultry cultivation and a treatment system thereof. The technology for treating sewage of livestock-poultry cultivation is characterized by the following steps included: 1) pretreatment of sewage is conducted; 2) the sewage after passing through an acidification adjustment basin stays in a red mud plastic anaerobic ferment device for 12-15 days for carrying out anaerobic ferment, the near medium temperature ferment process is utilized for removing the organic matters in the sewage, and the produced marsh gas is recycled; 3) the outlet water biogas liquid after anaerobic ferment enters a multi-level bionic oxidation channel, the residence time of the sewage in the multi-level bionic oxidation channel is 3-6 days, the organic matters are degraded, and nitrogen and phosphor are removed; 4) the outlet water after being treated by the multi-level bionic oxidation channel enters a multi-level artificial geological fast inleak system and goes through an infiltration medium from above to below by means of natural upright flow, and the outlet water is discharged in accord with standard. The technology and system is characterized by low cost, low energy consumption and high treatment efficiency.