NOVELTY - Polluted biogas liquor in livestock and poultry breeding is treated by transporting biogas from marsh gas pool to a primary settling tank; adding (colony forming units/ml) Bacillus FB-1 (1x 102 to 1x 103), photosynthetic bacteria preparation (1x 103 to 1x 104), FP-1 lactic acid bacteria preparation (1x 103 to 1x 104), FL-2 nitrification bacteria preparation (1x 102 to 1x 103) and denitrifying bacteria preparation FD-I (1x 103 to 1x 104) every 2 days.    USE - Method of treating a polluted biogas liquor in livestock and poultry breeding.    ADVANTAGE - The method has improved conversion efficiency, requires low investment and operation cost, and is simple.    DETAILED DESCRIPTION - Polluted biogas liquor in livestock and poultry breeding is treated by transporting biogas from marsh gas pool to a primary settling tank; adding (colony forming units/ml) Bacillus FB-1 (1x 102 to 1x 103), photosynthetic bacteria preparation (1x 103 to 1x 104), FP-1 lactic acid bacteria preparation (1x 103 to 1x 104), FL-2 nitrification bacteria preparation (1x 102 to 1x 103) and denitrifying bacteria preparation FD-I (1x 103 to 1x 104) every 2 days; reducing chemical oxygen demand content in the biogas slurry, removing partial nitrogen of biogas, removing smell of biogas liquid, and converting nitrogen and phosphorus nutrient salt proliferation bacteria body in the biogas to mycoprotein to obtain filter-feeding fish; adding FC-2 microbe liquid (2-5 g/m3) on secondary sedimentation tank, and discharging algae; adding (colony forming units/ml) FB-2 microbe preparation (1x 103 to 1x 104), photosynthetic bacterium preparation FP-2 (1x 103 to 1x 105), and FN-2 microbe preparation (1x 102 to 1x 103); and discharging slag and processed biogas, utilizing of biogas dregs, discharging processed biogas in accordance with standard, cleaning slag in the slag precipitation tank, fermenting slag in the primary sedimentation tank to obtain organic fertilizer via solid compost fermentation, drying heavy metal rich deposits of secondary precipitation pond, and using for road-making or brick-sintering materials.