：In the region of the western Loess Plateau, the practice of mulching has been implemented with the objective of reducing water losses in agricultural contexts. Nevertheless, there is currently a paucity of understanding and quantification of the impact of different mulching conditions on soil water evaporation. The soil water content (SWC) and the isotopic composition of soil and precipitation of Ziziphus jujuba were monitored on a continuous basis under different mulching conditions. The impact of diverse mulching techniques on soil evaporation was investigated through an analysis of their hydrogen and oxygen stable isotope characteristics and secondary index, lc-excess, in conjunction with the Craig-Gordon model. Despite the SWC of each experimental group being similar following a single irrigation event, the isotope values were all more depleted than those observed in the control check (CK). The evaporation loss rate of CK reached its peak on the second day after irrigation, at 16.15%. The evaporation loss of the thickness group demonstrated that T1 was the most effective, followed by T2 and then T3. In the particle size group, the evaporation loss peaked on the sixth day after irrigation, with G1 showing the highest loss at 8.83%, followed by G2 at 9.51% and then G3 at 10.55%. This suggests that the application of mulching sand will result in a reduction in the rate of evaporation. Furthermore, during the growth period of the date palm, the isotope values of T3 and G2 in the 0-30 cm soil layer were relatively depleted in comparison to the other experimental groups. The evaporation loss rates of the thickness groups were highest in May and August, with the highest rates observed in T1 (28.71% and 22.62%) and T2 (28.49% and 22.12%). T3 exhibited the lowest evaporation loss rates in this period, with a peak of 2%. The evaporation loss rate reached a minimum in October (T1: 16.10%; T2: 14.82%; T3: 13.72%), with the lowest value observed for the thickness groups (1.41% and 21.45%). The evaporation loss rate in May was greater than that in August for the particle size group. In particular, the evaporation loss rate of the sand-covered thickness group was significantly lower than that of the sand-covered particle size group. Therefore, adjusting the sand-covered thickness has a more pronounced effect on reducing evaporation and retaining moisture than adjusting the sand-covered particle size, and can more effectively enhance the utilization efficiency of agricultural water. The findings can contribute to a deeper comprehension of the sustainability of orchards in regions with constrained water resources, and provide a scientific foundation for the management of water resources in orchards in arid and semi-arid areas.