Small and micro wetlands are one of the most important freshwater habitats in the world. Their value lies not only in a single wetland but also in a watershed small and micro wetland network composed of a variety of small and micro wetlands, which play a significant role in freshwater biodiversity conservation. As a unique type of temporary small and micro wetland type in nature, the vernal pool is an essential part of the small and micro wetland network in the watershed, providing variously ecological service functions and making an essential contribution to human society. Nevertheless, there are few relevant studies on the vernal pool ecosystem at home and abroad, and this unique and vital small and micro wetland ecosystem has not attracted enough attention. This paper expounded on the concept and formation reasons of the vernal pool, and simultaneously summarized the hydrological characteristics of dry wet alternation of the vernal pool ecosystem. As well as revealed the characteristics of the vernal pool biological community, such as species composition, community structure, biodiversity, and community dynamics. The vernal pool can provide various ecosystem services, the maintenance of freshwater biodiversity in the watershed, the provision of species habitat, and hydrological regulation. Also, as the purification of water quality, other ecosystem services cannot be ignored. On this basis, problems and deficiencies in the research of the vernal pool ecosystem are discussed, and suggestions for the future development direction of this field are given.