Based on the design of the surface acoustic wave sensor electrode material on lithium niobate substrate, the threedimensional modeling of singlepair interdigital finger of surface acoustic wave sensor was carried out by COMSOL Multiphysics simulation analysis software, and the finite element simulation analysis of solid mechanics and electrostatic physics field was carried out. The results show that different electrode materials and thickness have great influence on antisymmetric mode frequency, symmetric mode frequency, admittance characteristic curve and impedance characteristic curve, and the effective suppression of parasitic resonance can be realized by changing the thickness of electrode material. The results provide a theoretical basis for further research.