Based on manual drill and oven drying method, this paper studied the variation of soil moisture, dried degree and restoration of dried layer, consumption and mechanism of soil moisture in dried layers in apple orchard in the depth of six meter in the area of Xianyang between 2002 and 2008. As the data shows that, during the drought years, the moisture amount is low with 7.3%-9.5% in the depth of 2.1 to 4.0 meter and 8.9%-11.6% at the depth of 4.1 to 6.0 meter, together with the growth of the long-term dried soil layers. The soil moisture improved significantly in the years 2003 and 2007 with rich rainfalls and replenishment, the figure rising to 18.8%-22.7% in the depth of 2.1 to 4.0 meter and 15.4%-18.2% in the depth of 4.1 to 6.0 meter, and the dried layers disappeared. Gravitational moisture is high in rainy years and can reach as deep as more than 2.0 meter. The gravitational water serves as the determining factor for the moisture recovery in dried soil layer and the stress of water film as the direct source. It is found that, in the research area, the moisture restoration of dried soil layers is rapid in the rainy years and the dried soil layers disappear after six months' moisture supply. Three stages can be found about the changes of moisture restoration of dried soil layers. In the first stage, the content of soil moisture increases between 0 m and 2 m and gravitational water appears, during which period, with the content of soil moisture exceeding 20%, part of the film moisture changes to the gravitational moisture, which can infiltrate into 2 meters in the same September. The second stage is the restoration of film water between 2 m and 4 m. When the gravitational moisture of 0-2 m moves to 2-4 m, owing to the low content of film water, the gravitational water changes to the film water and the water moves from upper soil to lower soil. The content of film water increases from about 8% to 16% in this stage. The third stage is the appearance of the gravitational water in the depths 2-4 m. While film water of 2-4 m increasing and exceeding 20%, part of the film water changes to gravitational water. The restored moisture content is reasonably high in this stage. Moisture restoration of dried soil layers of 4-6 m is similar to that of 2-4 m and can also be divided into three stages. But the restoration of dried soil layers between 4 m and 6 m is the result of the downward migration of the water of 2-4 m.In the case of annual mean rainfall up to 800 mm or above, the soil moisture can entirely meet the needs of artificial forest's growth regardless of how much the thickness of the loess will be. During the arid years, the volume of receipts of soil moisture in apple orchard was less than that of expenditure, thus resulting in a negative water balance without surplus water infiltrating into underground. During the wet years, on the contrary, the volume of receipts of soil moisture is higher than that of expenditure, causing a positive water balance with surplus water infiltrating into underground. In such rainy years with about 800 mm rainfall, the soil moisture replenishment can ensure a sustainable growth of artificial forests without long-term dried layer within three years. However the dried layer may appear three years later.