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 hierarchical cascade theory and a dispersion 2D-COM model of SAWs with a finite-length structure on the basis of rigorous mathematical analysis. The proposed approach can accurately and quickly calculate the influence of the propagation and aperture direction of the SAW device. The dispersion 2D-COM model facilitates the analysis of the suppression of spurious waves in SAW devices. Experimental results obtained from the design and implementation of the SAW filter 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.