Strong motion records with high recording qualities and basic site data were sought out from seismic records in various countries and regions, from which some typical long-period seismic waves were selected for analysis. Then, both the mean acceleration response spectrum and the fitted response spectrum based on long-period and general seismic records on different sites were analyzed and compared. After that, the fitted spectrum of seismic waves on soft sites was taken as the target, and its power spectrum density was iteratively calculated. The characteristics of acceleration power spectrum densities based on long-period seismic records were also analyzed. On this basis, with a super-long-span cable-stayed bridge as the background by applying ANSYS software to establish three-dimensional finite element model of the bridge structure, using power spectrum densities based on long-period seismic records and general seismic records as input, and utilizing the direct displacement pseudo-excitation method, the travelling wave effect of the super-long-span cable-stayed bridge under different apparent wave velocities was studied. The results have shown that the predominant frequency of power spectrum densities based on long-period seismic records is apparently lower than those based on general seismic records; the displacement response power spectrum values at the left tower top, the right tower top and the mid-deck under long-period seismic power spectrums are significantly larger than those under general seismic power spectrums, and the distribution of the displacement response power spectrum at tower tops is bimodality; and in this case, the travelling wave effect reduces the displacement and bending response values of the bridge structure.