NOVELTY - Production of biological organic fertilizer involves: mixing raw material comprising biological organic fertilizer using stirrer; crushing mixture into crusher process to less than 1 mm; granulating crushed material and primary granulating, disc granulating, pelletizing material, drying, into granule using dryer, removing dust and drying with de-dusting fan; secondary drying, by drying into dryer; and drying secondary dust, for second time into second dust-removing room, using second de-dusting fan; cooling, screening, coloring, coating and packaging.    USE - For production of biological organic fertilizer (claimed).    ADVANTAGE - The method produce biological organic fertilizer using two times drying, maintain product nutrient, can maintain a uniform product particles, with low crushing rate. Using underground dust exhausting system, reduces dust, smoke and dust pollution, and is beneficial to environment protection.    DETAILED DESCRIPTION - Production of biological organic fertilizer involves: mixing raw material comprising biological organic fertilizer using stirrer so as to each a raw material mix uniformly; crushing the mixture into the crusher process to less than 1 mm; granulating the crushed material into a granulator, adding proper amount of bond and a primary granulating, disc granulating, a granulator the making into a disk granulator, pelletizing the material, drying, into granule using dryer, removing dust and drying with de-dusting fan; secondary drying, by drying into a dryer; and drying the secondary dust, for second time into a second dust-removing room, using second de-dusting fan; cooling, the second de-dusting into the cooler and cooling to below 60 degrees C; screening the cooled vibration sieve into screen, with diameter of less than 5 mm to obtain qualified product, and product with diameter of more than 5 mm is send back to crusher, crushing again, granulating; coloring, the product with diameter of less than 5 mm into color machine and feeding qualified product according to a biological organic fertilizer; selecting a different pigment for qualified product of coloring; coating, the qualified product into the coloring machine, powder puff with powder or liquid coating to prevent the biological organic fertilizer agglomeration; packaging, the product using a machine into 40 kg bag. The steps fifth, sixth, seventh and eighth produces flue gas fly ash all entering into underground smoke exhausting system.