Ground motion involves significant nonstationary in time domain and frequency domain. The traditional uniform modulation model cannot fully characterize the nonstationary in both time domain and frequency domain, which debases the accuracy and precision of structural random vibration analysis. In order to overcome the above defects, a nonuniform modulated ground motion model is established, which is generated by the dot product of the multi-peak smooth intensity envelope and the nonstationary noise signal. The new model can fully represent the oscillation and attenuation characteristics of earthquake wave in time domain, at the same time, its spectral characteristics are close to the real values. Based on this study, the nonstationary evolution spectrum model is established, which simultaneously sets the time and frequency as variables. The analysis results show that these two models are superior to the uniform modulation model in both time domain and frequency domain. In view of the form and characteristics of the above seismic stochastic process model, the analytic method for solving the traditional structural vibration response is improved. Through a large number of examples, it is proved that the nonstationary characteristics in both time and frequency domains cannot be fully obtained when the structural random response is calculated according to the uniform modulation model, and the unsafe results are usually obtained. On the contrary, more accurate structural response characteristics and more detailed evolution process can be obtained when the two new improved models are used.