The study took heavy metal lead ions (Pb2+) as the research object, constructed dithizone-modified silver nanoparticles, and successfully realized the cyclic surface-enhanced Raman detection of lead ions by using redox method and surface enhanced Raman technology. The detection response range of functional materials to lead ions is 1nM~10μM, and the detection limit can reach 0.35nM. Using the method to detect lead ions in actual environmental water samples, the recovery rate is 91.6%~106.8%, and the relative standard deviation is between 4.1% and 7.9%. The method has the characteristics of convenience, rapidity and reusability, and has a huge application prospect in the rapid detection of heavy metal ions in environmental samples.