Against the global context marked by a steep decline and substantial loss of pollinating insects, urban green spaces have emerged as alternative refugia for these ecologically crucial insects, attributable to their capacity to maintain diversified microhabitats and sustained provision of abundant nectar and pollen resources. Strategic optimization of nectar and pollen plant configuration in urban landscaping could substantially enhance the conservation value of these green infrastructures for pollinator communities, while floral traits serve as critical sensory stimuli that mediate pollinator-plant recognition and flower-visiting selection processes. Employing the transect method, this study conducted a systematic investigation and analysis of floral traits in nectar and pollen plants alongside pollinator community assemblages across five urban green spaces in Beijing from March to September 2023, aiming to both explore the differences in floral trait preference among different pollinator functional groups and identify important floral traits affecting the changes in the visitation composition of each pollinator functional group. A total of 204 species of nectar and pollen plants were investigated in Beijing′s urban landscapes, whose floral traits exhibited substantial interspecific divergence in morphological diversity and large differences in pollinator attraction ability among different species. The investigation documented 141 pollinator species within Beijing′s urban green spaces, where six main functional groups—ants, solitary bees, honeybees, butterflies, hoverflies, and Coleoptera—demonstrated distinct preferential divergence in nectar and pollen plant selection and exhibited marked selectivity disparities toward specific floral traits. With flower characterized by capitula inflorescences, upright openings, tubular/tongue-shaped corollas, single-petaled structures, blue-purple coloration, and aromatic properties being preferentially targeted across multiple pollinator functional groups guild. The compositional variability in visitation patterns among main pollinator functional groups exhibited differential susceptibility to floral trait categories, with inflorescence type and corolla type exerting a predominant regulatory influence on floral selection behaviors across five major pollinator functional groups except butterflies. These findings enhance mechanistic comprehension of plant-pollinator interaction dynamics while providing empirical foundations for evidence-based selection of nectar and pollen plants and precision habitat engineering aimed at urban pollinator diversity conservation.