Abstract: Nitrite, as a commonly used color fixative and preservative in the food industry, poses a significant threat to public health due to its excessive use, necessitating safe, economical, and rapid detection techniques. Over the past decade, nanotechnology-derived materials (such as graphene-based materials, metal nanoparticles, metal oxides, and conducting polymer nanocomposites) have seen a remarkable increase in application for developing electrochemical sensors. Their high specific surface area, tunable electrocatalytic activity, and component synergistic effects have effectively enhanced the sensitivity, selectivity, and portability of sensors, providing key breakthroughs to address the limitations of traditional detection methods. This paper systematically reviews the latest advances in nanomaterial-based electrochemical sensors for food safety and environmental monitoring over the past decade: analyzing the interfacial interaction mechanisms of carbon-based/metal, metal oxide/conducting polymer composites, and their performance optimization for sensors. It covers the standards of sensitive, compact, and economical detection technologies, as well as challenges in practical applications. Studies have shown that the interface engineering design of nanomaterials is the core for enhancing the selectivity of sensors, and their tunable properties (such as electron transfer efficiency and surface adsorption capacity) have significantly improved the analytical performance of sensors. However, their large-scale application still faces bottlenecks such as material stability, cost control, and compatibility with multi-parameter detection, requiring further breakthroughs in material innovation and engineering adaptation in the future.