To achieve spurious wave suppression and its simulation for piezoelectric surface acoustic wave(SAW) devices with arbitrary piezoelectric complex film structure, this study derived the equation of hierarchicalcascade theory and a dispersion 2D-COM model of SAWs with a finite-length structure on the basis of rigorousmathematical analysis. The proposed approach can accurately and quickly calculate the influence of the propagationand aperture direction of the SAW device. The dispersion 2D-COM model facilitates the analysis of the suppressionof spurious waves in SAW devices. Experimental results obtained from the design and implementation of the SAWfilter with a 41°Y-X LiNbO3/SiO2/Si_poly/Si(111) structure were in good agreement with the simulation results,verifying the effectiveness and feasibility of the method.