Understanding the dynamics of soil nutrients and microbial diversity following vegetation restoration is fundamentally important for promoting the recovery of soil ecological function and revegetation in degraded karst ecosystems of Southwest China. Here, the study selected four vegetation types which represent four stages of vegetation restoration in a typical karst peak-cluster depression in Mulun natural reservein northwest Guangxi, i.e., grassland, shrubland, secondary forest and primary forest, and investigated soil pH, nutrient content, and the diversity of microorganisms in non-rhizosphere and rhizosphere soil around the dominant species. Significant differences in soil nutrients were observed between rhizosphere and non-rhizosphere at the four vegetation restoration stages. Soil available nutrients respond more sensitively to subtle changes in the rhizosphere than total nutrients. There was an enrichment effect for most soil nutrients. In addition, a dramatically higher accumulation rate was observed for available phosphorous (AP) and available potassium (AK) at primary forest, as compared to other three stages. Both the Shannon-Wiener index (H) and the richness index (S) for bacteria were higher than those for fungi, and the Shannon-Wiener index (H), the richness index (S), and the Pielou evenness index (EH) of bacteria and fungi in the rhizosphere were also higher than those in the non-rhizosphere. Soil total nitrogen (TN) was strongly correlated with pH value, soil organic carbon (SOC), and available nitrogen (AN) (P < 0.01), and phosphorous and potassium correlated positively with the diversity of soil microorganisms.