Based on the finite element method,the surface acoustic wave tag is simulated using COMSOL software.The substrate material is lithium niobate.The metal electrodes of the inter digital transducers and the reflectors are both made up of aluminum.By the frequency characteristic simulation,the resonant and anti resonant frequencies are extracted.The influence of the inter digital transducers metal electrode on the resonant frequency is analyzed,and the amplitude frequency curve is obtained.By the echo pulse characteristic simulation,the different echo pulses corresponding on different reflector encodings are researched. The influence of the reflector metal electrode on the echo pulse is analyzed.