A novel seismic reliability analysis approach of passive controlled MDOF structural systems subject to full non-stationary earthquake excitation, via the harmonic wavelet is presented in this paper. The structure is equipped with viscous fluid dampers which are widely used in the structural passive controlled structure. Specifically, a Power Spectral Density (PSD) relationship between the excitation and displacement response of controlled structure is firstly obtained, employing the Local Stationary Wavelet representation of non-stationary stochastic process. Next, storey drift reliabilities of distinct storey are calculated by the response PSDs and their moments based on the Markovian assumption of the crossing process. Finally, numerical simulations show that different distributions of viscous dampers may lead to distinct storey reliabilities. Pertinent Monte Carlo simulations show the reliability and accuracy of the proposed technique.