NOVELTY - Large-scale livestock farm sewage treatment is carried out by sending sewage to a three-level sedimentation tank, separating solid and liquid, and sending sewage liquid to a solar shed pool to deposit sludge; regulating water quality of sewage, pumping sewage to an upflow anaerobic sludge blanket (UASB) reactor to degrade macromolecular organic matter, conveying degraded sewage to an aerobic aeration tank, separating sludge and pumping sewage to a cascading biological oxidation pond; and conveying sewage to an aquatic plant oxidation pond for purification process.    USE - Method for large-scale livestock farm sewage treatment (claimed).    ADVANTAGE - The method can help in reducing the spread of disease caused by livestock farm waste, protect the environment, conserve water, and provide organic fertilizer to replace chemical fertilizer for improving soil.    DETAILED DESCRIPTION - Large-scale livestock farm sewage treatment comprises:    (A) dividing livestock farm waste into excrement and sewage, collecting excrement directly to a manure pile shed, and sending sewage after removing urine to a three-level sedimentation tank;    (B) discharging three-level sedimentation treated sewage to a sewage collecting well;    (C) intercepting solid particles and floating debris in the collecting well, then using lifting pump to pump the sewage into solid-liquid separation machine, sending separated solid to the pile of manure, and sending sewage liquid to a solar shed pool;    (D) warming sewage in the solar shed pool, depositing sludge, then using lifting pump to pump sewage to a regulating pool;    (E) regulating water quality of sewage in the regulating pool and pumping sewage to a upflow anaerobic sludge blanket (UASB) reactor;    (F) degrading sewage macromolecular organic matter in the UASB reactor into small molecular organic matter while producing marsh gas, entering marsh gas to a gas storage cabinet in the UASB reactor and then sending to a biogas tank, and sending small molecular organic matter into an anaerobic baffled pool;    (G) further degrading active organic matter in sewage in the anaerobic baffled pool, and conveying degraded sewage via a water pump to an aerobic aeration tank;    (H) aerating sewage using air blower and pumping sewage to a sedimentation tank;    (I) increasing dissolved oxygen in sewage sedimentation tank, separating sludge, and pumping sewage to a cascading oxidation pond to carry out biological contact oxidation;    (J) conveying sewage to an aquatic plant oxidation pond for further sewage purification process and for cultivation of aquatic plants to purify water; and    (K) directly conveying plant oxidation pond purified water for agricultural irrigation.