In this study, a microgreen space ecosystem in Arrow Pavilion green space that meets the comprehensive functional requirements of modern ecological living environments has been built in the Forbidden City, which can contribute to biodiversity enhancement in a green city. The study designed the ecosystem by extracting elements of regional flora and fauna adaptable to urban green spaces from ancient flower and bird paintings. The case showed respect for the traditional Chinese garden aesthetics and considered the special historical and cultural symbolism of the site. By selecting plants that are adaptable to the local climate and site conditions from the bird-and-flower paintings, combining them with landscaping stones, miniature wetlands, and composting facilities on 1-10-meter spatial scale, a multi-layered plant community reflecting the natural features of the region has been created and on 0.1-1-meter spatial scale, the miniature terrestrial and aquatic habitats have been constructed by referring to the composition of Chinese flower-and-bird paintings to meet the aesthetic requirements. After being built, the porous surface fully filled the spaces from the ground to the canopy, providing habitats for a variety of organisms to depend on. Non-discriminatory records were made on spontaneously growing plants, birds, insects, as well as mammals visiting the site. A total of 37 species of planted plants, 42 species of spontaneously-growing plants, and 29 species of animals were recorded. A complex food web comprising more than a hundred different organisms was generated. The flower bed also accommodates rare species, i.e., Snowy-browed Nuthatch (Sitta villosa), directly verifying that the multi-layer plant communities contribute to the improvement of the diversity of woodland birds on a 1～10 meter spatial scale. In the context of modern ecological civilization, this case is a practical example of integrating traditional aesthetics and biogeographical knowledge. It provides a way of thinking about urban biodiversity conservation and also the improvement and construction of the knowledge and technology system of Landscape Architecture.