Abstract: The present disclosure discloses a method for preparing a sludge conditioner from water supply sludge and a use of the sludge conditioner. The sludge conditioner is prepared by mixing the water supply sludge and sewage sludge. The method includes the following steps: mixing the water supply sludge and the sewage sludge in proportion, adding a pore forming agent, stirring a mixture uniformly, and conducting mechanical dehydration, air-drying, grinding, sieving, and pyrolysis to obtain the sludge conditioner. The conditioner is used in advanced oxidation technologies such as catalyzed/activated ozone oxidation, persulfate oxidation, and Fenton oxidation to condition the sludge and enhance dehydration performance.