The invention discloses a sludge curing agent with high water content. The curing agent consists of powder and comprises the following components in parts by weight: 12-15 parts of cement, 9-12 parts of pulverized fuel ash, 4-5 parts of quick lime and 1-2 parts of sodium silicate. The sludge curing agent is strong in adaptability to the sludge with water content being 80%-100% and capable of effectively improving shearing strength of sludge in projects of circling sea for building land, treatment of sludge of rivers and lakes and the like and improving the effective bearing capacity of sludge soil foundation with high water content being 80%-100%. The sludge curing agent can be used as curing agents in the process of processing soil foundations in projects of filling pits for building land and circling sea for building land and the like in fishponds and can be used for curing sludge generated by dredging and clearing sludge in rivers, lakes, fishponds and shores so as to prepare geotextile materials. By virtue of the sludge curing agent, the technical problems of high water content, low strength and great possibility of directly processing of hydraulic reclamation sludge with high water content in projects of circling sea for building land, building land and roads in fishponds can be well solved.