Abstract  [Aim]  Biodiversity is the foundation of life on earth, and insects represent the most diverse organisms. Maintaining the stability of the ecosystem is vital. The construction of the Three Gorges Project has attracted controversy due to its impact on biodiversity. Since the completion of the Three Gorges Project, no systematic research has been carried out on the insect diversity within the Three Gorges Dam Area. This study aimed to explore the diversity and density of insect species and their population distributions within the Three Gorges Dam Area. [Methods]  During May, August, and October of 2022, we sampled insect activity, including occurrence period, outbreak period, and overwinter period, in the Three Gorges Dam Area using transect lines, light traps, and Malay nets. [Results]  A total of 1 276 insects, belonging to 11 orders, 84 families, 158 genera, and 174 species, were collected from 84 transect lines, 4 light traps, and 3 Malay nets. The dominant groups were Lepidoptera, Coleoptera, and Hemiptera. Insect diversity analysis using the sample line method showed that the Shannon-Wiener index and Margalef richness index were the highest in the Rare Plant Research Demonstration Area of Binshui Island in the Three Gorges Dam Area, with 3.135 6 and 6.131 0, respectively. Furthermore, the Pielou evenness index was highest in the riverine area of the Three Gorges Dongyuemiao Big Data Center, with 0.983 0. [Conclusion]  The results indicate abundant insect resources in the Three Gorges Dam Area, including two species, Ypthima multistriata and Cheirotonus jansoni, listed in the China Species Red List as vulnerable (VU) and 16 species listed as insects of least concern (LC). Furthermore, the findings suggest that the ecological environment of the Three Gorges Dam Area is suitable for insect habitation and breeding.