[Objectives] Niche differentiation is a fundamental mechanism enabling the coexistence of sympatric species within shared habitats. This study investigates the niche differentiation strategies of four small and medium-sized carnivores—Viverricula indica, Prionodon pardicolor, Paguma larvata, and Prionailurus bengalensis—in the Baixi Provincial Nature Reserve, Zijin County, Guangdong. By analyzing their spatial and temporal niche dynamics, this work aims to inform conservation strategies for these endangered species. [Methods] From July 2020 to August 2022, camera trapping surveys were conducted to monitor four sympatric small and medium-sized carnivores in the Baixi Nature Reserve, with 72 camera traps placed in 51 grids of 1 km × 1 km. Spatial niche differentiation was quantified based on the spatial overlap index (IO). Kernel density estimation (KDE) was employed to model the diel activity patterns of the four carnivores, and overlapping coefficients (Δ) were calculated to compare the diel activity patterns among the four carnivores. Then, Wald tests were conducted to assess whether there were statistically significant differences in diel activity patterns among the four carnivores. The annual activity patterns of the four carnivores were assessed by the relative abundance index (IRA). Then, we performed Pearson correlation tests to assess the similarity in annual activity rhythms among the four carnivores. All statistical analyses were conducted in R 4.2.1. [Results] (1) In terms of spatial distribution, the IO values between V. indica and the other three small carnivores were lower (ranging from 0.20 to 0.38), while those among Prionodon pardicolor, Paguma larvata, and Prionailurus bengalensis were higher (ranging from 0.46 to 0.71) (Table 2). All the four carnivores showed a clear preference for evergreen broad-leaved forests, while Paguma larvata and Prionailurus bengalensis possessed more records of activities in other forests and shrubs (Fig. 3). (2) The diel activity pattern of V. indica significantly overlapped with those of Paguma larvata (Δ = 0.87) and Prionodon pardicolor (Δ = 0.83). Prionailurus bengalensis showed a different diel activity pattern compared with the other three carnivores (Δ ranging from 0.64 to 0.73, P < 0.01, Fig. 4). (3) The annual activity rhythms of the four animal species were fairly similar, while there were differences in the months when their peak activity occurred (Fig. 5). [Conclusion] The findings demonstrated that sympatric carnivores in the study area exhibited significant habitat preference overlap within comparable vegetation communities, resulting in pronounced interspecific competition pressures. This investigation provided novel insights into the temporal activity patterns and niche differentiation mechanisms among small and medium-sized carnivore guilds in South China, offering critical scientific support for developing regionally specific conservation strategies targeting endangered species within increasingly fragmented ecosystems.