Seasonal freezing and thawing is a major cause of serious soil salinization in Hetao irrigation area under climate change. In this paper, the Hetao irrigation area has been selected as an example and field monitoring experiments were used to analyze and study the dynamics of soil water, salt, and heat during freezing and thawing periods. The research results show that the unfrozen water presents a "concave" shape change, and as the degree of freezing deepens, the total water content continues to increase; the salt content also shows an increasing trend, with the 0 ~ 100 cm soil layer salt rate being 43.73%, of which 0 ~ 10 cm soil layer is 91.56%, followed by the 10 ~ 20 cm soil layer, which is 41.78%. The surface aggregation effect is obvious. The temperature data obtained by analysis shows that the freezing process is one-way freezing and the melting process is two-way melting. The above analysis results can provide a scientific basis for scientific planting and soil salinization prevention and control in irrigation areas.