Abstract: Soil microorganisms play an important role in the operation and maintenance of wetland ecosystems. In this paper, the PLFAs analysis method and high-throughput sequencing technology were used to obtain the community structure information of soil microorganisms and archaea. The changes of soil microbial biomass and archaeal community structure, and the influencing factors during the ecological restoration during returning farmland to wetland were discussed. The results showed that along the wetland restoration age, the biomass of soil total microorganisms, actinomycetes, bacteria and fungi (except for the 11 aW) in the surface layer increased continuously, while they showed a decreasing-increasing-decreasing trend in the subsurface layer. Compared with rapeseed field, the proportion of bacteria showed a decreasing-increasing-decreasing tendency in the surface soils of restoration wetlands, and showed a trend of increasing-decreasing in the subsurface soils. The proportion of fungi, and the ratio of fungi to bacteria showed a trend of increasing-decreasing-increasing along the restoration ages. The proportion of soil actinomycetes gradually increased along the restoration ages. Euryarchaeota (relative abundance: 47.61%-85.29%) was the first dominant phylum of archaea in the studied area, and Thaumarchaeota (relative abundance: 14.58%-52.33%) was the second dominant phylum. The relative abundance of the Crenarchaeota phyla was small (relative abundance: 0.01%-0.81%). The relative abundance of Euryarchaeota in the surface soil increased first and then decreased, and in the subsurface showed an upward trend during the wetland restoration period. The relative abundance of Thaumarchaeota showed a trend of decreasing-increasing in the surface soils, while has a decreasing trend in the subsurface soils. Correlation analysis and redundancy analysis results indicated that available nitrogen, total nitrogen and organic matter were the main environmental factors for explaining the changes of soil microbial biomass, microbial community structure and archaeal community structure during wetland restoration. However, the environmental factor with the largest cumulative explanations for changes of microbial biomass and community structure was soil available nitrogen. Microorganisms respond to the soil ecological restoration process in wetlands after returning farmland to wetland by adjusting microbial biomass and community structure.