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Soil dry layer has occurred widely in artificial economic forest in Loess region, which constrained vegetation restoration and reconstruction. In order to investigate deep soil depletion （below 2m） in densely planted jujube (Ziziphus jujube Mill.) orchard, soil coring method (Luoyang shovel) was used to get soil water content from surface to the maximum fine rooting depth at 0.2m soil interval. The results showed that root water uptake had a tendency to extend gradually deep, deep soil water depletion was 0, 29.6, 149.9 and 155.7mm in 2, 4, 9 and 12 year-old jujube plantation, deep soil water supply was 203.7, 167.7, 35.5 and 29.7mm, respectively, annual deep soil water depletion accounted for 0,2.3%,5.1% and 3.9% of annual soil water supply. There was almost no available water in 2~4m soil layer when the jujube plantation developed for 9 years. Jujube water requirement could not be met by the existing rainfall and drip irrigation amount. Soil dry layer extent and depth can be evaluated more accurately with the maximum rainfall infiltration depth and maximum fine rooting depth as upper and lower boundaries. Soil water content could be increased through water catchment, water conservation and water supplement, which played an important role in alleviating jujube plantation deep soil drying.