In order to explore soil water-salt dynamic interactions under the current condition of water-saving implementation in Hetao Irrigation District, the soil-water-atmosphere-plant (SWAP) model was calibrated and validated based on sunflower field experiments data, and then was applied to the simulation of soil water-salt flux and water-salt balance for the 0-100 cm soil layer with the plantation of sunflowers. The results showed that the water in the root layer of the sunflower farmland mainly leaked downward in irrigation period, the soil water flux and salt flux were both negative and the soil salt was leached out from this soil layer; whereas in the non-irrigation period, groundwater supplied upward for the water uptake of the roots, so the soil water flux and salt flux were both positive and salt accumulated in this soil layer. During the two-year simulation period, the annual water flux cumulant in the root layer soil reached 52.5 and 60.6 mm, the annual salt flux cumulant reached -4.5 and -4.9 mg/cm2 , and the annual total soil salt flux increased by 7.5 and 7.1 mg/cm2 , respectively in the 0-100 cm soil layer. Under the current irrigation regime, salt accumulates in the 0-100 cm soil layer, which would in turn cause the risks of secondary salinization of soil. So, it is suggested that an extra irrigation should be conducted at the end of sunflower growth period in autumn in order to leach out the soil salt for the growth of the next season of sunflowers.