Abstract: Nanjing City, is one of the 31 key flood control cities in the country. Due to the combined influence of geographical location, topographic features and climate, regional floods and basinal floods are extremely prone to occur. According to the spatial pattern of Nanjing and the urban characteristics of "hill, water, urban and forest", the characteristics of urban floods and the causes of disasters are analyzed. Centering on the development goal of "innovative famous city and beautiful ancient capital" in Nanjing, the relationship between urban flood and waterlogging, prevention standards and other aspects are analyzed. The paper puts forward countermeasures such as setting standards at different levels, optimizing urban layout, speeding up the construction of engineering system, strengthening management, improving urban emergency response plan, coordinating flood and waterlogging, and implementing joint drainage and dispatching.