Objective Considering the severity of both spring drought and spring cold, and shallow effective topsoil in the southern mountainous areas of Ningxia Province, synergistic effects of no tillage combined with mulching on improving soil moisture use and potato yield were investigated.Methods From 2014 to 2016, three different no-tillage mulching modes, including no-tillage straw mulching (NJ), no-tillage mulching film (ND), no-tillage no mulching (NB), and no-tillage no mulching as control (CK), were set up after autumn crops were harvested for three consecutive years. The effects of no-tillage with mulching mode on soil moisture retention, precipitation utilization and potato yield in arid region of southern Ningxia were analyzed.Results Soil water storage and water storage efficiency during the fallow period were the highest under ND treatment, which increased by 7.60% and 140.35% compared with CK, respectively; Those in normal year and dry year were the highest under NJ treatment, which were increased significantly by 11.18% and 65.43%, and 28.42% and 122.72% compared with CK, respectively. NJ treatment had the highest soil water storage from the seedling stage to harvest in normal and dry years, and from the budding stage to harvest in relatively dry years, which was increased by 10.51%, 12.89% and 20.04%, respectively, compared with CK. ND treatment significantly increased soil water storage by 11.42% compared with CK at the seedling stage in relatively dry years. The no-tillage and straw mulching treatment has the best soil water storage effect from the budding stage to swelling stage of potatoes in relatively dry years, specifically in the 100—140 cm layer, the 40—100 cm layer in normal years, the 0—40 cm layer in dry years, and the 100—160 cm layer. The no-tillage and plastic mulching treatment had the best soil water storage effect on the 180—200 cm layer in normal and dry years. The water consumption in ND treatment was 22.26% and 36.57% higher than that in CK in early growth stage (sowing-budding stage) and middle growth stage (budding-expanding stage) of relatively dry years, respectively. The water consumption in NJ treatment significantly increased by 1.21 times, 7.14 times and 13.91%, respectively, compared with CK, in the late growth period (expanding-harvest stage) and middle and late growth period (budding-harvest stage) of relative dry years and dry years, respectively. Potato yield was the highest in NJ treatment, which was significantly increased by 51.80% compared with CK. In normal years and dry years, potato yield of ND treatment significantly increased by 6.35% and 71.36% compared with CK, respectively. Through correlation analysis, it was found that water consumption during the seedling stage played an important role in potato yield, yield composition, and water use efficiency. The annual precipitation use efficiency, precipitation use efficiency and water use efficiency in the growth period were higher under NJ treatment than under CK, which were significantly increased by 51.79%, 51.80% and 50.52%, respectively; those under ND treatment significantly increased by 35.14%, 36.14% and 21.61% compared with CK in normal years and dry years, respectively.Conclusion No-tillage combined with mulching can effectively improve soil water storage and soil moisture retention during the fallow period and growth period, and significantly improve potato yield and water use efficiency. The no-tillage and straw mulching mode can realize continuous potato yield increase and high water use efficiency.