Abstract: Heavy metal ions, as one of the most common environmental contaminants in the food industry, pose a significant threat to public health due to their long-term accumulation. Although traditional detection techniques, such as atomic absorption spectrometry (AAS) and inductively coupled plasma mass spectrometry (ICP-MS), provide high analytical accuracy, their high cost, complicated operation procedures, and dependence on sophisticated instrumentation limit their application in rapid on-site screening. Over the past decade, the integration of nanotechnology has brought new opportunities for the development of electrochemical sensors. The high specific surface area, tunable electrocatalytic activity, and synergistic effects among different components have enabled significant breakthroughs in sensitivity, selectivity, and portability. This review systematically summarizes the major advances in nanomaterial-modified electrochemical sensors for food safety and environmental monitoring over the past decade. Particular attention is given to the interfacial mechanisms of composite materials, including carbon-based materials, metals and metal oxides, covalent organic frameworks (COFs), and metal-organic frameworks (MOFs), as well as their roles in improving sensor performance. Representative studies have demonstrated that the 3D GO/UiO-66-NH₂ composite enables the simultaneous detection of Cd²⁺, Pb²⁺, Cu²⁺, and Hg²⁺, achieving detection limits as low as 2.89-10.90 fM and a linear range of 0.01-0.35 pM, with recoveries ranging from 94.73% to 107.23% in rice, milk, and honey samples.Current evidence indicates that interfacial engineering is the key strategy for enhancing sensor selectivity, and that adjustable properties, such as electron transfer efficiency and surface adsorption capability, can significantly improve analytical performance. Nevertheless, the large-scale application of these sensors still faces challenges related to material stability, cost control, and compatibility for multi-parameter detection. Future research should further promote breakthroughs in both material innovation and engineering adaptation.