【Obiective】Focusing on the characteristics and dynamic mechanism of the same variation of surface soil water and its salt in different seasons in groundwater level buried depth area of the northwest inland basin, 【Methods】based on the comprehensive study of a series of in-situ monitoring data for many years,【Results and conclusions】the following conclusions are drawn: Surface soil moisture content of later spring,summer and early autumn are arranged in descending order. Day variation trends of moisture content of 20cm and 40cm depth soil are the same. Moisture content in later spring and summer presents decreasing tendency, which presents increasing tendency in early autumn. Surface soil pore water electronic conductivity later spring,summer and early autumn are arranged in increasing order. Day variation trends of electronic conductivity of 20cm and 40cm depth soil are different；The size changes of electronic conductivity of saturated leach solution (ECe) in three seasons have stratification differences. 40cm depth soil ECe in later spring,summer and early autumn are arranged in increasing order and 20cm depth soil ECe in three seasons are arranged in decreasing order. Daily changes of surface ECe in later spring period are stable in deep layer and present decreasing trend in shallow layer. In summer period daily changes of surface soil ECe present increasing trend in deep layer and present decreasing trend in shallow layer. In early autumn period day changes of surface ECe are stable in deep and shallow layers. (2) Irrigation can maintain moisture content of surface soil and elute its salty in later spring and summer. Evapotranspiration is the major factor of resulting in decreasing of surface soil moisture content and accumulating salt under high temperature in summer. The size of groundwater depth is a regulable factor of influencing the transporting water and salt from groundwater to topsoil. Condensation water has effect of leaching salt of 20cm depth soil. (3) Irrigation is the leading factor of surface soil moisture content in three seasons period. groundwater depth and of surface soil are important influencing factors. Moisture content and salty of 20cm depth soil are easily affected by condensation water. Irrigation is also an effective measure for leaching surface soil salt. Surface soil presents obvious salt deposition when irrigate stops in early autumn. Evapotranspiration is the key factor of surface soil deposition. The biggest increase of electronic conductivity of surface soil occurs in high temperature summer. Groundwater depth is an important and regulable factor. Therefore, the high temperature period from 9:00 to 19:00 every day in summer should be the main period to control and reduce the buried depth of the groundwater in farmland area to more than 1.9m, which can reduce the salt deposition rate and ensure that the salt content of topsoil is smaller than the salt tolerance threshold of crops.