Conventional chemical pesticides pose severe threats to global soil ecosystems, causing microbial dysbiosis, heavy metal accumulation, and long-term environmental degradation. To mitigate these ecological hazards, the green synthesis of biodegradable nanopesticides has emerged as a revolutionary, eco-friendly alternative. This review provides a comprehensive analysis of soil pollution driven by synthetic agrochemicals and explores the mechanisms of green synthesis using plant extracts, microbial matrices, and agricultural waste. Furthermore, it evaluates the environmental fate, soil degradation pathways, and biocompatibility of these green alternatives. By synthesizing current empirical data, this paper outlines the path forward for integrating biodegradable nanopesticides into sustainable agricultural frameworks.