In order to improve the refinement level of mechanical parameters of layered structures explored by Rayleigh wave,this study constructed the Rayleigh wave dispersion equation in layered elastic semi-infinite stratum based on the spectral element method.For the two stratum structures of semi-infinite and"upper soft and lower hard",compared and calculated the dispersion curves of multi-modes Rayleigh wave with spectral element method and fast vector-transfer algorithm.The results show that the relative error between the calculation results of spectral element method and the corresponding results of fast vector-transfer algorithm is under 0.05%,which has high calculation accuracy.On this basis,for the three complex layered structures of"upper hard and lower soft"pavement structure,containing"soft interlayer"and containing"hard interlayer",this study derived the calculation method of surface displacement based on spectral element method,and established an semi-analytical method to determine the superposition coupling mechanism of multi-modes Rayleigh wave in complex stratum structure by analyzing the contribution of each mode phase velocity of Rayleigh wave to surface displacement energy,which are in good agreement with the corresponding simulation results of velocity-stress finite element method,indicating that it is reasonable and feasible to calculate the dispersion curves of Rayleigh wave and reveal the superposition coupling mechanism of multi-modal Rayleigh wave based on spectral element method.