The desiccation of deep soil layer on the Loess Plateau results from the gradual depletion of storing water during the process of vegetation rehabilitation. How to assess quantitatively the desiccation of deep soil layer is of great importance to determine the reasonable vegetation type and density and guarantee vegetation rehabilitation. Combined soil water characteristic curve with specific soil water contents, the standards were preliminarily established for assessing the desiccation of deep soil layer on the Loess Plateau. Moreover, the standards were applied to assess the desiccation of deep soil layer on hillsides with locust on the loess tableland gully region.