[Aim]  Pieris rapae, the cabbage white butterfly, is widespread across China. The larvae cause significant damage to plants from the Brassicaceae, Oleaceae, and Asteraceae families. Adults serve as pollinators for some plant species and are a model species used in pollinator-plant-phytophagous insect interaction studies. [Methods]  DNA metabarcoding technology was used to analyze the diet and gut diversity of P. rapae in 3 urban green spaces which included the Henan University of Science and Technology (HKD), Luopu Autumn Garden (QFY), and Sui and Tang Botanical Garden (STY). [Results]  A total of 78 species belonging to 65 genera in 31 families were found to be host plants of P. rapae. Of the 3 plant classification levels including family, genus, and species, the relative abundance of Cruciferae (48.49 %), Brassica (31.62%), and Brassica oleracea (30.35%) were the highest. Alpha diversity analysis revealed that the community richness of HKD was significantly higher compared to QFY and STY (P<0.05). The QFY community diversity and dominant species concentration was significantly higher compared to HKF and STY (P<0.05). The beta diversity analysis showed there was no significant difference in the variety of plant species in the gut of P. rapae within each site. However, there was a significant difference between the sites. [Conclusion]  The findings of this study show that P. rapae uses different feeding strategies depending on the microhabitat. Moreover, the diversity of plants in the habitat is reflected in the gut contents of P. rapae. DNA macrobarcoding technology provides a new method to explore the cooperative coexistence mechanism between butterflies and habitat plants.