[Objective]After the August 8 earthquake, a large amount of vegetation in the Jiuzhaigou area was damaged, which seriously affected the stability of the local plant ecosystem, and the post-disaster ecological restoration was imminent. but a large amount of gravel soil produced after the disaster could not meet the basic growth requirements of plants because of its looseness, poor stability and other characteristics。 [Methods] so in this paper, Jiuzhaigou local cohesive soil and Jiuzhaigou area gravelly soil were mixed with different volume ratios, and soil water characteristics were investigated by soil-water characteristic curve test, moisture constant test, and soil column test to investigate the soil moisture characteristics under different ratios, and to select suitable soil mixing ratios for plant growth. [Results]The results show that: (1) The Van Genuchten model can fit the soil-water characteristic curve of improved gravel soil well, and the soil air-entry value increases with the increase of the proportion of cohesive soil, and the parameter α can characterize the state of the air-entry value to a certain extent. (2) The improved gravel soil increased the moisture absorption coefficient, wilting coefficient, field water holding capacity and saturated water content with the increase in the proportion of cohesive soil. The water availability and maximum effective water volume of the soil itself were increased, and the water availability of the improved gravelly soil with the addition of clay increased by 22.26-50.00 per cent and the maximum effective water volume by 70.96-131.46 per cent compared to the gravelly soil.. (3) Compared with the three models, the philip model has the best effect on soil water infiltration simulation, and the size of the uptake rate S can represent the change trend of the initial infiltration rate to a certain extent.[Conclusion]Comprehensive comparison of the moisture characteristics of different ratios of improved gravel soil, when the overlying soil layer is a water storage layer, the ratio of gravel soil to cohesive soil of 3:7 can be selected as the optimal ratio of improved gravel soil; when the overlying soil layer is a non-storage layer, which is not capable of storing water, the ratio of gravel soil to cohesive soil of 7:3 can be selected as the optimal ratio of improved gravel soil.