The airborne pollen produced by some plants in urban green spaces has allergenicity, which can cause pollen allergy among urban residents. Therefore, urban green spaces have become the main source and research area of urban pollen allergy problems.With the advancement of urbanization, pollen allergy is becoming increasingly common and poses a long-term risk, becoming a widely concerned health issue for urban residents. This article is based on the research hot spots and development trends of pollen allergy since the 20th century, summarizing the monitoring of urban green space allergenic pollen, evaluation methods of pollen allergy, influencing factors of pollen allergy, and prediction of pollen allergy risk. Regarding the unclear analysis and evaluation of the causes, regional differences, hazards and risks of pollen allergy, as well as the weak connection between research topics, the article systematically summarizes the collection methods, species and spatiotemporal distribution patterns of allergenic pollen, elucidates various methods and applicability conditions for evaluating pollen allergy, analyzes the urban ecological factors that affect pollen allergy, proposes pollen allergy risk warning and prevention measures, and points out the future development direction. The article can provide a basis for alleviating pollen allergy problems, optimizing solutions for preventing and controlling allergy risks, and providing scientific basis for establishing a pollen allergy research system, thereby reducing the adverse effects of pollen allergy on urban livability.