Abstract: Restoration of soil water in alfalfa-crop land was simulated in the hilly-arid region of southern Ningxia by a combination of survey and simulation methods. Simulated vertical distribution of soil water in different soil layers was consistent with observations and a good agreement was found between the simulated and observed soil moisture grades in different soil layers. A similar trend (higher speed at the earlier stage and lower speed at the later stage) was found in the process of forming and eliminating the soil desiccation layer. It was difficult for the restoration of soil water in 8-10 m soil. Therefore, soil moisture in this soil layer should not be lower than D grade, i.e. soil water content should not be less than 8.5% during the cultivation process of alfalfa. For the sustainable development of agricultural production, the appropriate alfalfa stand age was 6-8 years; the optimum subsequent cropping system to recover soil water was potato/potato/spring-wheat; and the appropriate cultivation years of this subsequent copping system was 16-20 years before alfalfa was replanted again.