Urbanization has led to a significant decline in global biodiversity, while green spaces are crucial in providing habitats for urban species. However, constructing large green spaces in limited urban ecological spaces is expensive. Micro green spaces offer a flexible layout and convenient location selection, making them a valuable supplement to the ecological space. To understand the research patterns and results of micro green space biodiversity, existing research has been reviewed and categorized into three areas: (1) the value of micro green space biodiversity in urban areas; (2) the mechanisms of the effects of micro green spaces on urban biodiversity; (3) ways to enhance micro green space biodiversity in urban areas. A systematic review and analysis meta-analysis of 39 articles were conducted, revealing revealed that: (1) Highly urbanized areas are hotspots for researching micro green biodiversity. (2) Bird research is the most prevalent, while mammal research is the least. The rich vegetation communities in micro green spaces can support insect diversity and provide food sources for urban birds. (3) Studies on vegetation coverage, vegetation abundance, and area factors are more frequent. Among them, area, green space ratio, vegetation richness, and vegetation abundance are positively correlated with microgreen biodiversity, while impervious surface area and noise are negatively correlated. (4) Promoting microgreen biodiversity can be effectively achieved by increasing vegetation abundance and enhancing habitat connectivity. These findings provide a scientific basis for developing habitat creation and layout planning strategies to enhance micro green space biodiversity.