Saline farmland in Hetao irrigation area is widely distributed with poor fertility and low productivity, which seriously threatens food security. In order to study the salt-control and water-saving effects of straw-water-retaining agent composite layer on saline-alkali soil in Hetao irrigation district, an indoor soil column simulation experiment was conducted with straw and composite layers under conventional (10 L) and 20% water-saving (8 L) irrigation water. Soil water infiltration, evaporation and salinity variation were determined and compared under different treatments. The results showed that both layers delayed water infiltration and improved salt leaching effect during infiltration process compared with CK (no interlayer and 10 L irrigation). Compared with straw layer, the composite one delayed water infiltration time by 14.47%, and increased salt leaching effect by 34.86% in 0-40 cm soil layer. In the evaporation process, the composite layer slowly released water to 20-40 cm soil layer through internal water retaining agent, and soil moisture in 20-40 cm layer was increased by 10.90%-90.61% compared with the straw layer. Under 20% water saving, the above effects in 0-40 cm soil was better for the treatments with composite layers than CK. In summary, the composite barrier of straw and water retaining agent has better effect on water and salt control than straw barrier even under the condition of water saving, which provide basis and reference for the reduction of water-saving saline-alkali barrier in Hetao irrigation district.