Ecological restoration has increased vegetation cover and reduced soil erosion, but it has also resulted in decreased soil-moisture content (SMC) and increased soil desiccation, which has ultimately led to a weakening of the soil reservoir function and a decline in the growth of plantations. Thus, soil desiccation has been a serious threat to the sustainable utilization of soil water resources and vegetation rehabilitation. In this study, the soil moisture of a Robinia pseudoacacia forest as well as its corresponding soil desiccation to a depth of 500 cm were measured across three different precipitation zones (400-450, 500-550 and 550-600 mm) along a north-south transect on the Loess Plateau. The results showed that the soil-moisture environment and soil desiccation status generally improved with the increasing precipitation gradient, while soil-moisture over-consumption significantly declined (p < 0.05). However, due to the elder forest-stand age and severe growth recession, the soil desiccation of R. pseudoacacia in the northern part was less than that in central zones. As the forest-stand age increased, SMC of R. pseudoacacia increased firstly and then decreased, and both soil-moisture consumption and the average soil desiccation rate peaked in the RP-5a, showing no significant consistence with forest-stand age. Therefore, understanding the soil-moisture status of forestland may better provide scientific basis for native vegetation restoration and reconstruction in water-limited regions.