Background: The golden apple snail (Pomacea canaliculata), an invasive species originating from South America, has inflicted considerable agricultural and ecological harm in non-native habitats. While the molluscicide niclosamide is currently effective against P. canaliculata, its prolonged use raises environmental concerns and the risk of resistance development. Results: BAM 15 possesses strong molluscicidal activity against P. canaliculata, with 72 h LC₅₀ values of 0.4564 mg/L for adults (shell height: 20–25 mm), 0.3352 mg/L for subadults (10–15 mm), and 0.1142 mg/L for juveniles (2–3 mm). Metabolomic and proteomic profiling revealed that the altered metabolites and proteins both converged on energy metabolism and oxidative stress. Experimental validation revealed that BAM15 collapsed the mitochondrial membrane potential, drove MDA and H₂O₂ upward while depleting NADPH, boosted CAT, SOD and GPX activities, yet suppressed GR, and ultimately inflicted overt damage in the head-foot tissue of P. canaliculata. Conclusions: Our findings reveal that BAM 15 operates via a three-stage mechanism: (1) it disrupts membrane potential (ΔΨm) and impairs ATP production, severely disturbing energy metabolism; (2) energy deficits stimulate excessive electron transport chain activity, generating reactive oxygen species (ROS) and initiating oxidative stress; (3) persistent metabolic imbalance and oxidative damage culminate in extensive tissue injury. These results identify BAM 15 as a promising candidate for molluscicide development.