Coastal wetland ecosystems, located at the boundary of land and sea, are characterized by high biodiversity, high primary productivity, active nutrient element cycling driven by microbes, and important sources of nitrous oxide (N2O) emissions. N2O is the third greenhouse gas only less than carbon dioxide (CO2) and methane (CH4), and it is estimated that microbes are responsible for more than 90% of global N2O emissions, which are closely associated with the diversity, composition and function of microbial communities involved in nitrogen cycling in coastal wetland ecosystems. This review focuses on microbially-driven N2O production and mechanisms that are coupled with carbon, sulfur and metal cycling, temporal and spatial patterns of N2O emissions regulated by environmental factors, and future research directions in coastal wetland ecosystems, aiming to reveal microbially-driven N2O production and regulatory mechanisms by environmental factors, and mitigate global warming.