[Objective] The evolution characteristics of soil microorganism in the process of vegetation restoration in Loess Plateau were studied in order to which provided scientific reference for the ecological restoration and reconstruction of the loess plateau.[Methods] The present study focused on the vegetation restoration in the Loess Plateau and made a systematic analysis of soil microorganism evolution based on the literature data from the database of "Web of Science" and the "China National Knowledge Infrastructure" using CiteSpace bibliometrics tools.[Results] The number of literatures related to soil microorganism during the vegetation restoration of Loess Plateau during 2002-2018 presented an increasing trend. The related works mainly focuses on the soil microbial biomass, microbial community structure, enzyme activities, and especially on the microbial biomass. Vegetation succession caused an increase in microbial biomass and enzyme activities and led to a succession from oligotrophic microbial community to eutrophic community. In general, soil microbial community structure and function was improved during the vegetation succession. Vegetation types had different effects on soil biological quality. The mixed forest had the best quality, followed by the Robinia pseudoacacia and Caragana korshinskii pure forest, abandoned grassland, and Pinus tabuliformis pure forest.[Conclusion] Research on the soil microorganisms in the vegetation restoration of Loess Plateau in the future should focus on the key identification of soil microbial taxa in microbes involved in the carbon, nitrogen and phosphorus cycling, and the impact of global changes on the microbial community.