Abstract: In order to investigate the effects of freeze-thaw process on the adsorption and desorption of selenate (Se (VI)), black soil was subjected to freezing and thawing treatments with different moisture and cycles through indoor simulation. The soil after freezing and thawing was used for Se (VI) adsorption and desorption experiments. In addition Langumuir and Freundlich were respectively used to fit the process of Se (VI) adsorption. The results showed that both freezing and thawing significantly (P < 0.05) changed the pH value, organic matter, glomalin-related soil protein, and aggregate content of each particle size of the black soil in Northeast China.The amount of Se (VI) adsorption in the soil after freezing and thawing was significantly higher than that in the unfreezing and thawing soil. It is found that the adsorption of Se (VI) in black soil is more in line with the Langmuir model (R² > 0.967). Both the high initial moisture content and the number of freeze-thaw cycles increased the maximum adsorption capacity, buffer capacity of black soil to Se (VI) and the desorption rate of Se (VI). The 70% of moisture content and multiple freeze-thaw cycles increased the adsorption potential of black soil for Se (VI), promoted the desorption of Se (VI), and increased the bioavailability of selenium in the soil, which would facilitate the absorption of selenium by crop roots.