The Index of Biotic Integrity integrates the response characteristics of several individual indicators to disturbances, thus offering has good indicator stability and response sensitivity in comprehensively evaluating the health status of water ecosystems. There are many cases of water ecological health evaluation of natural rivers using the biotic integrity index, but there are relatively few studies evaluating urban rivers due to the variability in water body characteristics affecting indicator selection. Building on previous studies and considering the unique characteristics of urban rivers, this study incorporated functional diversity indicators, which reflect ecosystem functions, into the alternative index system, constructed an index for evaluating the integrity of macroinvertebrates in urban rivers in Tianjin, and carried out the evaluation of water ecological health. Based on the water ecology monitoring data from April and September 2023, the changes in the macroinvertebrates community structure of urban rivers in Tianjin were analyzed between dry and water abundant periods. The results showed that macroinvertebrates community composition exhibited significant seasonal differences (ANOSIM: P=0.006, R=0.107), with species richness being higher in dry periods than in water abundant periods. The number of species was higher in the dry period than in the abundant period for the pear-shaped ringed snail (Bellamya purificata, Y _{dry period}=0.208, Y _{abundant period}=0.192), one species of ringed snail (Bellamya sp., Y _{dry period}=0.045, Y _{abundant period}=0.074), and one species of striated marsh snail (Parafossarulus striatulus, Y _{dry period}=0.033, Y _{abundant period}=0.164). These species were all dominant, showing seasonal stability. In this study, the macroinvertebrate biological integrity index (IBI) of urban rivers in Tianjin was constructed using the number of aquatic insect taxonomic units, the BMWP index, functional richness, and functional differentiation as the core evaluation indexes. The evaluation results reflect the importance of introducing functional parameters in the construction of biological integrity. In terms of spatial distribution, the upper reaches of the river maintained better biotic integrity characteristics, while the middle and lower reaches were generally affected due to anthropogenic interventions. In terms of seasonal variation, there were differences in integrity changes in different areas, with reference sites having intact habitats, high vegetation cover, and high functional diversity showing better resistance and resilience to external disturbances, and therefore experiencing less hydrological disturbance. In contrast, impaired sites generally had reduced biological integrity. Both nutrient salts and organic pollution affected the IBI index in both seasons, and hydrological changes were also important factors that should not be ignored for macroinvertebrate communities during the abundant water period. The results provide a reference basis for the evaluation, protection, and restoration of river ecosystems in Tianjin from the perspective of biological integrity, and also serve as a reference for other similar river ecosystems.