Assessing the status of wetland health can provide critical information for the protection and management of wetland ecosystems. The benthic macroinvertebrate-based index of biotic integrity (B-IBI), is a comprehensive method for assessing the ecological health of wetlands. Benthic macroinvertebrates are the most widely used biological indicators owing to their distinct advantages for freshwater biomonitoring, including bottom-dwelling habits, their relatively immobile nature, and huge species diversity. In this study, we aim to develop a benthic macroinvertebrate-based index of biotic integrity (B-IBI) to assess the health condition of Poyang Lake wetland. Field surveys of 30 sampling sites were conducted in the autumn of 2015. We collected data covering benthic macroinvertebrate species identity, abundance, water quality parameters, soil properties, and land use surrounding the sampling sites. We tested 49 candidate metrics with respect to the diversity, structure, and disturbance tolerance of benthic macroinvertebrate communities, for their discriminatory ability between the least disturbed and impaired sites. Five metrics were finally selected as the B-IBI metrics:number of taxa, number of Ephemeroptera, Trichoptera, and Odonata (ETO) taxa, Simpson's diversity index, number of Diptera individuals, and number of predator taxa. Values of these metrics were scaled between 0 and 1. The B-IBI score of a sampling site was calculated as the sum of the scaled values of each individual metric. B-IBI scores were judged as five categories:excellent, good, fair, poor, and very poor. The results showed that four sites were rated as excellent (3.75 ≤ B-IBI); six were good (2.51 ≤ B-IBI ≤ 3.74); two were fair (1.92 ≤ B-IBI ≤ 2.50); eight were poor (1.02 ≤ B-IBI ≤ 1.91); and ten were very poor (B-IBI ≤ 1.01). Sampling sites rated as excellent and good were mostly located in western sections, especially within the national nature reserves, while those rated as poor and very poor were mostly located in northern, eastern, and southern sections, where wetland health was impaired by dense population and intensive agriculture practices. Wetland areas where rivers discharge into Poyang Lake were generally rated as poor, suggesting that pollutants brought in by rivers have negative impacts on wetland health. B-IBI assessment was significantly correlated with values generated from other methods (Pearson's r ranging between 0.43 and 0.57, P < 0.05), including the index of landscape development intensity (LDI), the qualitative habitat evaluation index (QHEI), and the vegetation-based IBI (V-IBI), suggesting that the results of these methods are generally consistent but not identical. Using multiple methods may generate more comprehensive results for the assessment of the wetland health status of Poyang Lake.