Abstract: Xinjiang's cotton industry plays an important role in global cotton production. However, the current strategy of surface drip irrigation cannot meet the high efficiency water saving and salt leaching requirement, seriously limiting sustainable development. Therefore, a field experiment was conducted in 2021 to explore the effects of surface-subsurface relay drip irrigation on soil water and salt movement, crop growth, cotton seed yield, desalination efficiency and irrigation water use efficiency in saline soil. The experiment based on crop water requirment (ET_c) and leaching amount included three irrigation levels of 0.8ET_c+120 mm (W1), 0.8ET_c+240 mm (W2) and 0.8ET_c+360 mm (W3), and three irrigation water level distribution modes of 100% surface drip (membrane under drip irrigation) irrigation (F1), 75% surface drip irrigation + 25% subsurface drip irrigation (F2), and 25% surface drip irrigation + 75% subsurface drip irrigation (F3). Finally, the feasibility was verified by the water-salt numerical model. The soil water content (SWC), soil salt content (SS), crop growth and seed yield were determined. The results showed that different irrigation level and distribution modes significantly affected soil water and salt distribution, cotton growth and yield (P<0.05). Under the low irrigation level treatment (W1), the soil desalination and desalination efficiency of each distribution mode were low, making it unsuitable for salt leaching and achieving high crop yields. Under the medium irrigation level treatment (W2), the average soil moisture content for F2 and F3 was 2.11% and 6.69% higher than F1, with the average soil salt content decreased by 33.43% and 21.41%, with desalination efficiency increasing by 4.53 and 3.06 times, respectively. Under the high irrigation level treatment (W3), the relay drip irrigation significantly improved soil water and salt conditions compared to drip irrigation under the film mulching. Due to better water and salt conditions, under the medium (W2) and high (W3) water treatments, the seed cotton yield of F2 and F3 was significantly higher than that of F1. The F2 ranked the highest, followed by F3 and F1. As the irrigation level increased, the seed cotton yield, irrigation water productivity and desalination efficiency under the surface-subsurface relay drip irrigation were significantly better than drip irrigation under the film mulching . Optimal conditions were found with an leaching level of 222-282 mm, the ratio of surface drip irrigation to subsurface drip irrigation was 1.00-1.94, resulting in the best comprehensive benefits for soil salinity, yield and irrigation water use efficiency in saline cotton fields. This study provides a theoretical basis for the implementation of relay drip irrigation in saline areas of Xinjiang.