Urban greenspace exposure has been regarded as a nature-based solution to address potential health risks resulting from changes in human living environments and lifestyle. The integration of public health into the entire process of urban greenspace planning, design, construction, and management constitute a pivotal approach to achieve the United Nations Sustainable Development Goal (SDG) 11 of Sustainable Cities and Communities. Under the initiative of Healthy China, it is the foundation of urban greenspace high-quality development and management to understand the mechanism among greenspace planning & design interventions and health effects. Based on the perspective of planning and design, this study adopts the bibliometric and meta-analysis method to systematically review literatures about urban greenspace exposure and its health effects. Greenspace types, spatial scales, exposure dimensions and measurement approaches are summarized along with the associated pathways to promote human health. And a framework linking urban greenspace planning & design, exposure characteristics and health benefits is constructed. Using the Normalized Difference Vegetation Index (NDVI) as the core exposure metric, the study further explores the nonlinear dose-response relationship and the exposure threshold between greenspace exposure distance and health outcomes. The key findings are listed as follows:(1) Focal exposure characteristics were different at the planning and design level. Most studies at planning level focused on the spatial configuration of overall greenspaces through objective measurements, while studies at design level focused on internal landscape elements and spatial arrangements, mainly by measuring residents' subjective perceptions and behaviors. (2) Pathways linking greenspace exposure and health outcomes were varying. At planning level, spatial configuration (including the availability, accessibility, and visibility) and ecosystem services of urban greenspace affecting built environmental quality and residents' perceptions and behaviors, resulted in directly or indirectly associated with public health outcomes. At design level, configuration characteristics of natural elements (e.g., trees, lawns, water bodies) and facilities (e.g., plazas, benches, sports areas) inside urban greenspace were associated with direct health effects such as stress reduction and physical activities promotion. Pathways mentioned above were moderated by socio-economic and environmental contexts and may exhibit variability under different conditions. (3) Dose-response relationship and its exposure distance threshold existed between NDVI and health outcomes. As for physical health, the health effect observed within the buffer radius of 100 meters was the most significant (OR=0.72), while the OR value observed within the buffer radius of 500 meters and 1000 meters decreased to 0.95 and then increased to 0.90. However, the physical health effect was not obvious between 500 meters and 1000 meters. As for mental health, the health effect observed within the buffer radius of 300 meters was the most significant (OR=0.87), and the health effect decreased with the increase of the buffer radius, approaching ineffectively at the buffer radius of 1000 meters (OR=1.08). The range of mental health effects of green space exposure (500m) was smaller than that of physical health (1000m). It is hoped that more empirical research on urban green space exposure and its health effects is conducted to clarify the key indicators and measures for supporting urban greenspace planning and design practices to promote residents' health in the future.