To understand the diversity characteristics and interannual variations of the fish community in the middle reaches and tributaries of the Huishui River during the early stage of the fishing ban, fish resource surveys were conducted from 2021 to 2023. A total of 59 fish species were collected, belonging to 40 genera, 12 families, and 7 orders. Among them, Cyprinidae fish were in an absolute dominant position, accounting for 67.80% of the total species, 89.22% of total abundance, and 91.65% of total biomass. The ecological types are dominated by benthic, omnivorous, and spawn-laying fish, with the proportions of species being 55.93%, 55.93%, and 44.07% respectively. Interannual characteristics showed that species richness ranged from 35 to 49, among which the common dominant species were Zacco platypus and Acrossocheilus fasciatus. The Margalef index, Shannon-Wiener index, and Pielou index all showed a fluctuating upward trend overall, ranging from 4.18—5.34, 1.97—2.37, and 0.55—0.62, respectively, while the Simpson index showed a downward trend from 0.19 to 0.31. Cluster analysis showed that community structure in spring, summer, and winter of 2021 was similar, as was that in winter of 2022 and winter of 2023; all other sampling occasions grouped together. This suggests that community recovery followed distinct phases, with a unique response pattern in the early stage (2021). Spatially, the main stream and tributaries generally formed separate clusters, indicating that habitat-driven differences remained dominant. Overall, the recovery of community structure was driven by multiple factors under temporal dynamics, including habitat conditions and seasonal variation, exhibiting phased progression and spatial heterogeneity. This research clarifies the characteristics and diversity trends of the fish community in the Huishui River during the initial stage of the fishing ban, providing a basis for the assessment of the fishing ban effect and the scientific management of aquatic biological resources.