The characteristics and formation mechanism of resource islands in arid and semi-arid regions were widely reported. However, the effect of resource islands on community stability and vegetation natural restoration on burned area was still unclear. We investigated restoration of Tamarix ramosissima and vegetation under the shrub canopies on burned area. The shrub size index (SSI) and composite resilience index were established to study relationships between resource islands, vegetation restoration, and diversity of vegetation under the canopies. We quantified resilience stability of shrubs with different SSI. The results indicated that:(1) soil organic matter and soil moisture content were obviously higher under and at the edge of canopies than those outside the canopies, which formed resource island. The maximum value of soil organic matter was found in 0-10 cm soil layer. The phenomenon of fertilizer accumulation was the most obvious in middle T. ramosissima. (2) Soil salinity was mainly composed of neutral salt. The soluble salt in the soil layer of 0-40 cm under canopies was significantly lower than that outside the canopies. It showed obvious characteristics of salt valley in soil under shrubs. It was easy to observe this phenomenon for the middle shrubs. (3) With the increase of SSI of dead standing T. ramosissima, the number and height of branches increased, and the height, coverage, density, and biomass of vegetation under the shrubs were significantly higher than those outside the shrubs. The larger shrubs were, the better effect of the natural recovery was. (4) With the increase of SSI, Simpson index, Shannons-Wiener index, Margalef index, and Pielou index of vegetation under the canopies decreased firstly and then rose, with low diversity index and the simple community structure. (5) Composite resilience index showed a trend of firstly ascending and then descending with the increase of SSI. The value of community stability of T. ramosissima shrub was the highest when SSI was equal to 52.17. Community stability was mainly maintained by the restoration of herbaceous plants when shrubs were small on burned area. With the increase of SSI, community stability was maintained by the restoration of shrubs. The soil environment with high nutrient and low salt was formed from shrubs, which contributed to the restoration of vegetation. Resource island also played a positive role in maintaining the diversity and stability of plant communities. It was of great significance to vegetation recovery on burned area and ecological protection of desert ecosystem.