The Yarlung Zangbo River is the largest river on the Tibetan Plateau in China. It nurtures a variety of endemic, rare, and valuable species and is a key area for global biodiversity research. However, in recent years, other natural disasters, such as mudslides within the Yarlung Zangbo River Grand Canyon (above the Motuo reach), have led to a serious decline in fishery resources in the mainstream. Benthic macroinvertebrates are an important component of river ecosystems; however, their biodiversity has not been investigated properly, and most studies are clearly inadequate at the spatial and temporal scales. To characterize the benthic macroinvertebrate community structure of the Motuo reach of the Yarlung Zangbo River Grand Canyon in Tibet, the species composition in the Motuo reach and its affiliated tributaries were investigated in October-November 2022 (autumn) and April-May 2023 (spring), and the spatial and temporal distributions of their community structure and diversity were analyzed. The results showed that 52 species of benthic macroinvertebrates, belonging to 3 phyla, 3 classes, 10 orders, and 30 families, were collected in spring and autumn. Compared with the results of a previous study, the number of benthic macroinvertebrate species was greatly reduced. Among these, aquatic insects are dominant (50 species). In addition, the dominant species in spring were Baetis sp.1 and Lepidostoma sp., whereas Baetis sp.1 and Potamyia sp. were dominant in autumn. The macrobenthic community composition differed somewhat between spring and autumn (P＜0.001). The total average abundance of benthic macroinvertebrates in the basin was 6.67 ind/m² and the total average biomass was 0.04 g/m² in autumn. Meanwhile, the total average abundance in spring was higher than that in autumn (at 8.71 ind/m² ), and the total average biomass was 0.04 g/m² . Macrobenthic biodiversity showed some differences in both the main streams and tributaries during the different seasons (P＜0.01), which may be related to water quantity and habitat stability. Natural disasters, such as mudslides, are the most significant cause of such consequences. Compared with published data (2015‒2016) and combined with the current status of water environmental factors, the dominant species of macrobenthos have significantly changed, and the total abundance and biomass of species have significantly decreased, indicating that the habitat of aquatic organisms was disturbed after the disaster. The results of this study help map the current status of benthic macroinvertebrate resources in the Motuo reach of the Yarlung Zangbo Grand Canyon in Tibet after the 2017 mudslide and provide a reference basis for biodiversity conservation in plateau regions. However, it is necessary to conduct correlation analyses in conjunction with several environmental factors to identify the key factors influencing differences in the macrobenthic community structure in subsequent studies.