The urban water system has a dual characteristic of "nature-society", which includes the natural water cycle and social water cycle. In recent years, China has made the tremendous achievements in the field of water service engineering construction, but there are still shortcomings in terms of foresight, ecology, systematicity and integrity. The top-level design and key technologies of water service systems guided by ecology intelligence are discussed. Based on a new generation of information technologies such as cloud computing, the internet of things and big data, a smart water platform that integrates air and earth is built, including the smart water supply, smart sewage, smart drainage and waterlogging prevention, and smart sponge city, to overcome the shortcomings of urban water service systems in terms of foresight, ecology, systematicity and integrity in order to improve the water resource efficiency, improve the water environment quality, provide the water safety guarantees and restore the water ecological functions.