NOVELTY - Method for reducing pathogenic microorganisms in sludge from sewage treatment plant, involves (a) collecting remained sludge after sewage treatment process into the sludge treatment tank, (b) irradiating the sludge, (c) performing anaerobic digestion in order to remove residual pathogenic microorganisms in sludge after microwave pretreatment, (d) performing high-pressure carbon dioxide treatment in order to remove residual pathogenic microorganisms in sludge after anaerobic digestion, and (e) composting the sludge by earthworms.    USE - The method is useful for reducing pathogenic microorganisms in sludge from sewage treatment plant.    DETAILED DESCRIPTION - Method for reducing pathogenic microorganisms in sludge from sewage treatment plant, involves (a) collecting remained sludge after sewage treatment process into the sludge treatment tank, (b) irradiating the sludge which is in sludge treatment tank at 60-80 degrees C for 2 minutes with 2000-3000 MHz of microwave, where the microwave power is 500-1000 W, the microwave heating can rise the environment temperature of the bacteria, and promote the moisture in the cells to heat at the same time, making the protein of the cell produce denaturation, thus killing the pathogenic microorganisms, and removing the activity eggs and fecal coliform efficiently, (c) performing anaerobic digestion in order to remove residual pathogenic microorganisms in sludge after microwave pretreatment, continuing to perform anaerobic digestion, discharging the sludge after microwave treatment into the anaerobic digestion tank for anaerobic digestion, obtaining use of the heat which is released in process of the organic oxidation by the microorganism to inactivate the pathogenic microorganisms, the anaerobic digestion has obvious effect on killing the fecal coliform and Salmonella, so that multiple pathogen is reduced 59.7-93%, but it has no obvious effect to the ova of roundworm, (d) performing high-pressure carbon dioxide treatment in order to remove residual pathogenic microorganisms in sludge after anaerobic digestion, continuing to perform high-pressure carbon dioxide treatment, discharging the sludge after the anaerobic digestion into a disinfection tank for disinfection, injecting carbon dioxide gas with the pressure of 5-10 Mpa in disinfection tank, and mechanically stirring the sludge to be treated fully for 10-20 minutes, and releasing the pressure by the pipe, where the carbon dioxide solubility is rapidly reduced while the pressure is reduced and a large amount of carbon dioxide gas in the disinfection tank escapes rapidly in a high-pressure state, the gas is diffused and dissolved inside the microbial cell, in which the carbon dioxide gas changes into gas fast in the process of pressure release, the explosion phenomenon happens inside the microbial cell, the cell structure and cell membrane of the microbial cell are destroyed, the cell contents are leaked, and thus the microorganism is killed, and (e) composting the sludge by earthworms after the high-pressure carbon dioxide treatment, discharging the sludge into the composting tank for composting after the high-pressure carbon dioxide treatment, inoculating the earthworms, and taking the excreta as organic fertilizer, catching the earthworms and processing into feed for use uniformly in fertilizing period.