Nitrous oxide(N₂O), an important greenhouse gas, has a global warming potential of 265 times higher than that of an equivalent concentration of carbon dioxide. The N₂O has a long atmospheric lifetime and does deplete the ozone layer in the stratosphere. Agricultural soil is an important source of N₂O, which has a characteristic of diverse generation paths, multiple impact factors, and complicated regulation processes. Mitigation of N₂O emissions from agricultural soils has long been the hotspot of research in this field. N₂O-reducing bacteria harboring N₂O reductase can reduce N₂O to dinitrogen(N₂), which is the only known sink of N₂O consumption as a primary substrate in the biosphere. The direct use of microorganisms to decrease N₂O emissions from agricultural soils is an emerging technology. We elaborated on the biological sources and sinks of N₂O emissions from agricultural soils in detail, paying special emphasis on the screening and application strategies of microorganisms that can mitigate N₂O emissions. There are three strategies for the direct use of microorganisms to decrease N₂O emissions from agricultural soils: (1) application of the prepared microbial inoculum directly to the agricultural soil; (2) combination of the prepared microbial inoculum with fertilizers or other carriers before being applied to the soil; (3) construction of the microbial community with N₂O mitigation effect, and then direct application to the soil or in combination with a carrier before being applied to the soil. We summarized two ecological mechanisms of microbial-mediated mitigation of N₂O emissions from agricultural soils. One mechanism involved employing N₂O-reducing bacteria containing nosZ gene to directly convert N₂O to N₂ in order to mitigate N₂O emissions from agricultural soils. The other mechanism utilizes plant growth-promoting rhizobacteria to alter the community composition, abundance and activity of the N₂O-reducing bacteria and indirectly mitigate N₂O emissions from agricultural soils. We also discussed the environmental factors that affect the reduction of N₂O to N₂ by directly using microorganisms and the potential challenges. The biological process of reducing N₂O to N₂ is affected by many environmental factors, including the availability of NO₃^- and carbon sources, oxygen concentration, moisture content, temperature, pH and copper concentration. Among them, Cu availability and pH are some of the most important factors that determine the activity of N₂OR. Several issues need to be addressed in future studies. For example, there are only a limited number of strains that have been screened with N₂O mitigating effects. It remains unknown whether the inoculum colonizes roots or survive in the environment after the inoculation. The microbial ecological mechanisms are poorly understood; such as, how the inoculum achieve their beneficial effects in environments. Moreover, we lack effective technical means to regulate the inoculum to fully exploit their beneficial effects. Further, the methods to evaluate N₂O mitigating effects also need to be improved. Finally, prospects on the application of microbial-mediated mitigation of N₂O emissions from agricultural soils were suggested. The review provides an important technical reference for achieving the agricultural carbon neutrality strategic goal in China.