Plaster slurry of clay-cement can be widely used in seepage and leakage prevention and foundation strengthening in civil and hydraulic engineering. Its rheological properties have important influence on the construction and performance of grouting projects. The influences of curing agent’s content, temperature, and time on the rheological properties of clay-cement plaster slurry were researched by testing the rheological parameters through Brookfield+R/S rheometer. Results revealed that 1) the viscosity and yield stress of the slurry increased with time; 2) when the dosage of curing agent reached about 1.0% of cement mass, plaster slurry had optimum anti-seepage performance and belonged to Herschel-Bulkey fluid; 3) at temperature ranging from 5-40 ℃, temperature had impact on the viscosity and yield stress of the slurry, but had no effect on the fluidity, and the higher temperature led to larger viscosity, and in the meantime yield stress reached its maximum at 28 ℃. Through indoor grouting simulation test and anti-scour test, clay-cement plaster slurry was verified to have good water-dilution resistance and controllable diffusion range. Compared with pure cement slurry, clay-cement plaster slurry has larger initial yield stress and viscosity and better stability with controllable thixotropy. It is a preferred material for the seepage prevention in grouting of complex strata such as water-bearing and large-porosity strata as well as loose and soft strata.