Abstract: Hormesis is an adaptive response in which organisms exposed to sub-toxic doses of stressors exhibit enhanced growth, metabolism, or stress tolerance. This phenomenon has recently shown significant potential for agricultural applications. This review systematically summarizes the molecular regulatory mechanisms, major application fields, and recent research progress of hormesis in agriculture. At the plant level, low doses of pesticides, heavy metals, and other toxic substances can promote photosynthesis, root development, and antioxidant capacity. However, such stimulatory effects are strictly concentration-dependent,  and the ecological risks posed by bioaccumulation should be taken seriously. At the farmland ecosystem level, hormesis is widespread and multifaceted, displaying marked species specificity and concentration thresholds. Some low-dose pollutants may even affect plant population dynamics and agroecosystem stability through transgenerational effects. In the context of pest and disease management, hormesis exhibits a dual nature: sublethal doses of pesticides often alter pest reproduction and migratory behavior, thereby becoming a driving factor for resistance evolution; conversely, the same doses tend to be safer for natural enemies. In summary, hormesis represents a bidirectional regulatory strategy of biological systems near toxicity thresholds, carrying both beneficial and risky attributes. Future research should focus on establishing precise threshold determination models, exploring the use of hormesis for precision pest control and resistance management, and improving corresponding ecological risk assessment systems, thereby promoting green, precise, and sustainable agricultural production.