The rheological properties of modified clay slurry before and after the addition of accelerant,as well as consolidation mechanism of the slurry are discussed in this paper.The analysis shows that shear-thinning effect of the slurry be beneficial to grouting engineering,the plastic strength of modified clay slurry is affected mainly by the thickness of original clay slurry,the contents of accelerant and structural additive,the rheological properties and water-plugging property of the modified clay slurry are obviously better than the one of cement slurry.