Through measuring and analyzing salinities’ physical and chemical characteristics of Gobi soil near the Mogao Grottoes, we discovered that soil salinity had a great impact on the vertical distribution of soil water content. The content distribution, physical and chemical characteristics of crystal salinities, which was represented by mirabilite, tallied closely with the distribution of soil moisture. The depth from 0 to 20 cm was mainly dominated by anhydrous salinities (Na2SO4), and water content was relatively low, it was salt concentration layer. The depth from 20 to 50 cm was mainly dominated by crystal salinities (Na2SO4·10H2O), and water content was relatively high, it was salt precipitation layer. The depth of below 50 cm was mainly dominated by filmy salt solution, and water content was relatively low. Compared with near dune which had low salinity, salinity caused water content of Gobi soil increased by 10 times more. Under thermokinetics action, water movement was greatly increased in shallow soil. It is important to the upright water transport and ground water evaporation of GSPAC system. This offers a new way to ecological recovery by using ground water and also important to protect Mogao grottoes cultural relics.