Pesticide ecological safety continues to be a hot issue. The inherent biosafety and physiological functions of vanillin, a widely used natural flavor in food additives, have unlocked numerous applications in the medical field, leading to a plethora of pharmaceutically active derivatives and commercial drugs. Despite its extensive use in pharmaceutical discovery and the food industry, vanillin’s potential in the domain of green pesticide development has only recently come to light. Significantly, its advantages of safety and low price make vanillin ideal for green pesticide research and development (R&D). In this context, this review illuminates the research on vanillin’s transformation into a suite of innovative agrochemicals. By delving into the design, synthesis, action mechanisms, and bio-safety of these vanillin-derived compounds, we uncover novel pathways for sustainable agriculture. Further possible directions for the exploration of this substance are also outlined. We believe that this story about vanillin will serve as a source of inspiration for those seeking to derive innovative ideas from natural substances, particularly in the realm of green pesticide R&D.