[Objective] The soil water characteristics of the mixture of landslide gravel soil and local sedimentary cohesive soil in different proportions in Jiuzhai Valley after the "8·8" earthquake in 2017, were analyzed, and the best improved gravel soil suitable for plant growth in the study area was selected in order to provide scientific basis for ecological environment restoration after earthquake in Jiuzhai Valley region.[Methods] A local clay soil from Jiuzhai Valley and gravel soil from the Jiuzhai Valley region were mixed at different volume ratios, and soil water characteristics were investigated by soil water characteristic curve test, water constant test, and soil column test to investigate the soil water characteristics under the different mixing ratios in order to select soil mixing ratios suitable for plant growth.[Results] ① The van Genuchten model was able to fit the soil-water characteristic curve of the improved gravel soil well, and the soil air-entry value increased as the proportion of clay soil increased. The parameter α characterized the state of the air-entry value to a certain extent. ② The improved gravel soil increased the water absorption coefficient, wilting coefficient, field water-holding capacity and saturated water content as the proportion of clay soil increased. The water availability and maximum effective water volume of the gravel soil increased by 22.26 %~50.00 % with the addition of clay soil (compared with the gravel soil), and the maximum effective water volume similarly increased by 70.96 %~131.46 %. ③ Of the three models evaluated, the Philip model simulated soil water infiltration the best, and the size of the uptake rate (S) can represent the change trend of the initial infiltration rate to a certain extent.[Conclusion] Comprehensive comparisons of the water characteristics of different ratios of improved gravel soil showed that, when the overlying soil layer is a water storage layer, a gravel soil to clay soil ratio of 7:3 can be selected as the optimal ratio for improved gravel soil. When the overlying soil layer is a non-storage layer that is not capable of storing water, a gravel soil to clay soil ratio of 3:7 can be selected as the optimal ratio for improved gravel soil.