Carrying out research on urban wetland biodiversity is of great significance for protecting urban wetland protection and promoting the sustainable development of wetland resources. In view of this，this paper selects typical wetlands in Chengdu to carry out biodiversity survey and research，and the results are as follows. In typical wetlands，there are 200 species belonging to 147 genera and 61 families of wetland plants，243 species belonging to 64 families and 28 orders of birds，and 15 species belonging to 5 families and 3 orders of small mammals. In typical wetlands，plants are mainly hygrophytes，accounting for 91.50% of the total species of wetland plants；typical wetland birds（swimming birds and wading birds）account for 30.04% of the total species of wetland birds；small mammals are mainly rodents，accounting for 60.00% of the species of small mammals. Typical wetlands are dominated by local wetland plants（174 species）and there are 26 alien species. In general，typical wetlands have high plant species diversity，bird species diversity，and a certain small mammal species diversity，indicating that typical wetlands generally have a good ecological environment and can contribute to the biodiversity of Chengdu. Conservation provides habitat and food resources，but the protection of rare species and the management of harmful species still need to be strengthened.