[en] In order to investigate Magnesium-Potassium Phosphate Cement (MKPC) mixed with silica fume on the solidification and reduction of high moisture content (94%) of municipal sludge. The moisture content of the solidified sludge, volume shrinkage, compressive strength and other properties were studied, and the mechanism was discussed based on phase and morphology analysis. The results indicates that the solidified sludge (30% MKPC) with 30% silica fume can obtain with the early compressive strength of 430 KPa, which reached the requirements of the landfill (≥ 350 KPa). The moisture content of solidified sludge decrease to 30% and the volume shrinkage of solidified sludge can reduce to 68% or less at 7d, which played a key role for sludge reduction. MKPC and silica fume form skeleton structure that can promote the evaporation of moisture in the sludge. (paper)