The residual soil of Sericite schist softens and becomes loose when encountering water, which is easy to be damaged by wetting. Its engineering properties are obviously affected by water, so it is necessary to study its soil water characteristics. In this paper, the matric suction of Sericite schist residual soil under different dry density is measured by filter paper method. It is found that the change of soil water characteristic curve of Sericite climbing residual soil is not typical “s”, and there is no obvious unsaturated residual section. The main reason is that the residual soil of Sericite schist has sheet structure, easy drainage channel and fast water loss speed, the change of matrix suction is large. Because of its lamellar structure, its water holding capacity is poor, so the unsaturated residual section of its soil water characteristic curve has no obvious change.