Abstract: The preparation of compound hydrolases for detergent from excess activated sludge was studied. The sludge was mixed with 2.0-fold water containing 1% Triton X-100 and stirred for 60 min. The rate of protease extraction was 71.7%. After membrane filtration and concentration, the enzyme extract was precipitated with 70% ethanol and freeze-dried to powder. Enzyme powder of 1.7 g was obtained from 1 kg sludge and the powder had an enzyme activity of 4.216, 3.714, 11.915, 3.060 and 1.291 U/mg for collagenase, alkaline protease, lipase, amylase and cellulose, respectively. The stability and the shelf life of the enzymes was greatly improved with the addition of an optimized complex stabilizer which consisted of 4% sucrose, 4% mannitol, 30 mmol/L glycine and 10 mmol/L magnesium sulfate. The commercial enzyme granules for detergent were prepared according to the formula of 4% composite enzyme powder, 10% diatomite, 10% soluble starch, 6% composite stabilizer and 70% sodium sulfate decahydrate. The main types of enzymes and the activities of enzyme granule preparation were similar to those of the commercial detergent enzyme preparation on the market. This study provides a new way for the utilization of activated sludge.