The invention relates to a composite biological enzyme preparation for the deweighting treatment of domestic sludge, and a production and application method thereof. The invention is characterized in that 100-500 kilograms of composite biological enzyme for the deweighting treatment of domestic sludge are used for 100 thousand tons of municipal domestic sewage, wherein the composite biological enzyme for the deweighting treatment of domestic sludge comprises 25-30 parts of protease, 20-25 parts of one or more of laccase, polyphenol oxidase and manganese peroxidase, 17-21 parts of one or more of xylanase, pentosanase and mannase, 20-25 parts of one or more of cellulase, pectinase and hemicellulase, 10-15 parts of lipase and 12-16 parts of amylase. Compared with the prior art, the invention removes hydrogen sulfide gas and undesirable odor thereof, simultaneously eliminates the inhibiting effect of H2S on the nitrification process, effectively reduces nitrate and ammonia, decomposes proteins, starch, fat, food oil, xylan, cellulose and other organic substances, converts suspended substances, accumulated waste and soluble organic substances in the sludge into carbon dioxide, nitrogen gas, oxygen gas, water and sulphate, reduces the TSS (Total Suspended Solids), COD (Chemical Oxygen Demand) and BOD (Biochemical Oxygen Demand), greatly decreases the yield of the sludge, and has the advantages of no poison, no corrosiveness and no secondary pollution production.