Ecological environment is the foundation for human survival and development, and the construction of big data smart management and service platform for the urban ecological environment is a requirement for the construction of ecological cities and beautiful cities. This paper takes Shenzhen City as an example, with the help of the internet of things technology, mobile Internet, computer technology, database technology, Web Geographic Information System service technology (WebGIS), as well as key technologies such as spatio-temporal and geographic big data integration and sharing, big data mining and analysis, and cloud-integrated business collaboration technologies, combined with urban ecosystem assessment analysis decision model/method/countermeasure library. Based on the effective integration of Shenzhen's multi-source heterogeneous ecological big data such as "space, ground, Net, Statistics, Crowd Sources", we built an ecological field data survey collection system and an urban ecological monitoring and evaluation management decision-making analysis system for professional users such as business departments and scientific researchers, as well as a Shenzhen city ecological survey APP for the general public. We realized the whole process and integrated a value-based technology system for ecological big data of "data collection, information extraction, knowledge mining, decision generation, fast service", and built a smart management and service platform for Shenzhen's ecological big data. The platform revealed the changes in the pattern, composition, process, service, and health of different ecosystems in Shenzhen since 1979 for the first time. It has improved the scientific and comprehensive decision-making of the ecological environment in Shenzhen city, the precision of the ecological environment supervision, and the convenience of public services for the ecological environment. The platform effectively reduced the difficulty of user data collection and processing, and the difficulty of professional model operation, so could break through the bottlenecks and difficulties of original data application, and increase the use rate of professional models in business departments. The platform is no longer the simple display of raw data and monitoring data but is the full mining and rapid service of implicit, previously unknown, and potentially valuable information or knowledge in Shenzhen's ecological big data. In the future, the evolution of technical solutions from mining data to knowledge based on "ecological environment big data and ecological professional model" is the crucial element to manage ecological big data in urban areas more smartly and professionally, and it is also important to comprehensively improve the level of urban ecological environmental protection informatization services way.