Salix psammophila is an excellent windbreak and sand-fixing native tree species in Hobq Desert. [Objective]The aim was to reveal the biological mechanism of shrubbery on soil in sandy area.[ Method ] In this paper, S.psammophila with different forest ages ( 6 years, 12 years and 15 years ) was used as the research object. In early July 2023, the soil of 0-10 cm, 10-20 cm and 20-30 cm soil depth under S.psammophila forest in Hobq Desert was collected, and the main physical and chemical properties and enzyme activities of the soil were analyzed to provide a scientific basis for revealing the mechanism of vegetation restoration on soil in this area.[ Results ] ① With the increase of forest age, compared with the control, the content of fine particles increased gradually, and the soil bulk density and pH value decreased. ② Soil nutrients and enzyme activities showed obvious surface aggregation in the vertical direction.There were significant differences in soil nutrients and enzyme activities among different ages of S.psammophila ( P < 0.05 ).The soil alkali-hydrolyzable nitrogen, available phosphorus, available potassium, alkaline phosphatase activity and catalase activity in the 12-year S.psammophila forest were 316.4 %, 420.3 %, 134.6 %, 164.5 % and 94.8 % of the bare sand, respectively.The organic carbon, urease activity and invertase activity under the S.psammophila in the 15 years increased by 186.2 %, 145.3 % and 2703.4 % compared with the CK. ③ Soil enzyme activity was closely related to soil alkali-hydrolyzable nitrogen, available phosphorus, available potassium and organic carbon in different forest age restoration stages.[ Conclusion ] After the construction of S.psammophila shelter forest in Hobq Desert, it has a significant improvement effect on soil nutrients and enzyme activities.