NOVELTY - Dry solid biomass that can be decomposed by microorganism is granulized to obtain granules smaller than 100 mm. The granules are filled to a container with a bearing layer and a water distribution device to form a fixed bed microorganism reactor. Sludge from a sewage treatment plant, and sulfate reducing bacteria are taken. The microorganism is cultivated and propagated by taking ferrous sulfate aqueous solution as the inlet water. The microorganism is domesticated to adapt the environment of the biomass filler fixed bed.    USE - Method for treating acid wastewater containing heavy metal and recovering heavy metal by biomass fixed bed.    ADVANTAGE - The method of treating acid wastewater containing heavy metal and recovering heavy metal by biomass fixed bed are carried out efficiently and economically.    DETAILED DESCRIPTION - Dry solid biomass that can be decomposed by microorganism is granulized to obtain granules smaller than 100 mm. The granules are filled to a container with a bearing layer and a water distribution device to form a fixed bed microorganism reactor. Sludge from a sewage treatment plant, sludge from pond, sludge from river or sludge from wastewater treating pond, and sulfate reducing bacteria as source of microorganism strain are taken. The microorganism is cultivated and propagated by reflux circulation of the outlet water or taking ferrous sulfate aqueous solution with concentration of sulfate radical of 500-3000 mg/L as the inlet water. The microorganism is domesticated to adapt the environment of the biomass filler fixed bed, till the oxidation-reduction potential of the outlet water is lower than -150 mv, the acid drainage water containing heavy metal is led to the fixed bed to be directly filtered. The filtering speed of the fixed bed will gradually reduce along with the increase of the precipitation of the heavy metal, and the operation is stopped and the mass in the fixed bed is taken out in case that the filtering speed cannot meet the requirement of design. Smelting is carried out to recover heavy metal, and the fixed bed microorganism reactor is re-filled.