Abstract: With the widespread use of succinate dehydrogenase inhibitor (SDHI) fungicides in agriculture, their frequent detection in aquatic environments has raised increasing concerns about their toxicity to aquatic organisms. However, current research on the combined effects of temperature variation and SDHI fungicides on aquatic organisms remains limited. In this study, zebrafish (Danio rerio) were used as model aquatic organisms, and two representative SDHI fungicides, boscalid and flutolanil, were selected for investigation. A static exposure method was employed to assess the acute toxic effects of these fungicides on zebrafish at different temperatures. The results showed that under conditions of 18℃, 28℃, and 38℃, the 96-h LC₅₀ values of boscalid for zebrafish embryos were 2.428, 2.649, and 0.387 mg/L, respectively; and those of flutolanil were 4.358, 4.482, and 0.516 mg/L, respectively. These results indicate that high temperature (38℃) significantly enhances the lethal effects of both boscalid and flutolanil on zebrafish embryos. Observations of embryonic development revealed that high temperature (38℃) accelerates developmental processes, as evidenced by faster somite formation, while a low temperature (18℃) delays development, characterized by abnormal pigmentation, impaired somite formation, pericardial edema, and yolk sac edema. Furthermore, measurements of oxidative stress-related enzyme activities demonstrated that under high-temperature conditions (38℃) , exposure to both boscalid and flutolanil significantly increased levels of reactive oxygen species (ROS), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) in zebrafish embryos. This suggests that high temperature exacerbates oxidative stress responses in zebrafish embryos, leading to oxidative damage and thereby intensifying the adverse effects of these fungicides on early embryonic development.