Function strains have been used for carrying out shake-flash reduction test of the second pond sludge which were derived from citric acid fermentation wastewater. The strains were acclimated by adding sterile original sludge with different concentrations. The optimum cultivate conditions of the strains processing were determined by the orthogonal and single factor tests. Experimental results indicated that the percentage of sludge MLSS reduction with the processing by W1-6 and W1-10 were improved obviously ...