Freeze-thaw (FT) cycles significantly stress crops in Northeast China, exacerbated by pesticide overuse, particularly affecting vulnerable seedlings during these periods. This study investigates the physiological responses of Secale cereale L. seedlings to the insecticide imidacloprid (IMI) and the fungicide triadimefon (T) under simulated FT conditions. Our findings reveal that both pesticides impair photosynthesis in FT environments, resulting in increased malondialdehyde (MDA) and relative conductivity (RC). Furthermore, exposure to IMI and T enhances the activities of superoxide dismutase (SOD), peroxidase (POD), and ascorbate peroxidase (APX), while decreasing reduced glutathione (GSH) and hydrogen peroxide (H