Urban green spaces are the principal manifestation of urban green infrastructure and nature-based solutions (NBS), providing diverse ecosystem services for citizens. Urban green space exposure research focusing on human health and green spaces pattern has emerged as a hotspot in urban ecology and sustainable urban development disciplines. Currently, exposure to human health in urban green spaces is preliminary, lacking valid and acknowledged research paradigms. This paper attempts to review research milestones and advances in green space exposure and human health from the perspective of exposure science. (1) From the perspective of urban green space exposure characteristics, green space exposure research is significantly different from the perspective of existing traditional environmental health research which aimed at preventing and reducing the exposure risk of environmental pollution. Its goal is to fully understand the characteristics of green space exposure and the mechanism of its health effects, and encourage and improve the effective and beneficial contact between urban residents and green space, serving the scientific planning and decision-making of urban green space and healthy community construction. (2) From the quantitative representation of urban green space exposure, the existing multiple green space exposure indicators, including green space availability, green space accessibility, and green space visibility, mostly represent the supply status of green space, rather than the direct description of the urban residents’ green space exposure process. In the future, we can refer to the total exposure mathematical equation to comprehensively quantify different approaches, visit periods, exposure duration, and other factors based on spatiotemporal dynamic model of urban green space exposure. (3) From the perspective of the health effect mechanism of urban green space exposure, the current research on the health effect mechanism of green space exposure has not obtained many general theoretical results. The main challenges are: the exposure characteristic indicators used in different green space health effects research being different, the green space exposure affecting the health of people with significant scale effect, and the lack of unified green space exposure investigation methods. The role of green space in urban planning and construction is particularly prominent, but the population health promotion function of green space is rarely applied in urban planning and construction in China. Urban green space exposure and human health effect are the frontier fields of urban ecology and environmental risk, public health and sustainable development. Relevant achievements will provide directly scientific basis and theoretical support for guiding the health-oriented sustainable urban/community planning and construction.