NOVELTY - Method for cleaning harmless compost, involves mixing municipal domestic sludge and dry agricultural organic waste to obtain compost material, adding high temperature aerobic bacteria to the compost material, adding the obtained mixture to fermentation tank to obtain fermentation pile, heating the fermentation pile compost material, maintaining temperature of the fermentation pile compost material between 55 degrees C and 65 degrees C for 7-10 days, and degrading organic flocculant material in the fermentation pile compost material.    USE - The method is useful for cleaning harmless compost for municipal domestic sludge.    ADVANTAGE - The method is rapid and environmentally-friendly, eliminates epidemic danger caused by city pollution, recycles waste products, and process municipal sludge to organic fertilizer.    DETAILED DESCRIPTION - Method for cleaning harmless compost, involves (1) mixing municipal domestic sludge and dry agricultural organic waste in a ratio of 4:1 to obtain compost material, (2) adding high temperature aerobic bacteria to the compost material, stirring the mixture, and adding the stirred mixture to fermentation tank to obtain a fermentation pile, (3) ventilating and heating the fermentation pile, (4) terminating ventilation process and heating when temperature of the fermentation pile compost material is above 35 degrees C, (5) decomposing organic matter using aerobic microorganism to release energy, heating fermentation pile compost material continuously, reducing temperature of the fermentation pile compost material when the temperature is 65 degrees C, (6) terminating the ventilation process when the temperature of the fermentation pile compost material is 55 degrees C, and (7) repeating step (5) and (6), maintaining temperature of the fermentation pile compost material between 55 degrees C and 65 degrees C for 7-10 days, and degrading organic flocculant material in the fermentation pile compost material to improve physical characteristics of sludge.