To understand the impact of more than 40 years of afforestation of Pinus sylvestris plantation on soil water and salt in the southern edge of Horqin sandy land, based on the soil and meteorological data of P. sylvestris forest land and grassland from March 2020 to November 2021 in Horqin sandy land, the double cumulative curve method (DCM) was used to verify the rationality of sample plot selection, the spatial instead of time method (STM) was used to study the variation pattern of soil water content and salinity in P. sylvestris forest land and grassland and the differences in their correlation with meteorological factors. P. sylvestris forest changed the distribution of water and salt in the longitudinal profile of the soil, both tended to be in a positive "S" shape. Forest effectively increased soil water storage (p<0.05), reduced soil salinity, and reduced the range of water sub active layer. The variability of forest soil water was higher (p<0.05), while the variability of salinity was lower (p>0.05). The correlation degree between the meteorological factors and soil moisture and salinity indicators in forest was different from that in grassland, weakening the correlation with rainfall and increasing the correlation coefficient with water vapor pressure deficit. These results indicated that P. sylvestris forest ecosystem had a strong function of water conservation and soil salinization inhibition.