A treatment technology of black liquor and bleaching liquor from straw pulping process was studied in the paper. Firstly, the black liquor was treated by flocculation and filtration methods. And lignin and suspension solid etc were separated out. Then clear black liquor was mixed with bleaching liquor and treated with activated sludge process. The final flow had COD below 400 mg/L and could meet the demand of Chinese Pollution Effluent Standard in pulping process.