This study aims to effectively restrain the effect of parametric perturbations on operating performance for Contactless Power Transfer (CPT) system. A generalized state-space averaging method based on frequency domain decomposition is applied. By this method, CPT system is approximately a linear time-invariant system and then a linear fractional transformation of GSSA model and its parametric uncertainties is discussed to generate a linear dynamic system with the perturbed feedback. Aimed at this generalized system with the structured parametric uncertainties, the D-K iteration method is proposed for designing a μ-synthesis controller based on the Structured Singular Value (SSV).The simulation and experimental results show that μ-synthesis control system has a certain dynamic performance and robustness and can not only rapidly restrain the effect of frequency and load perturbations on the system itself but also accurately track the steady value of output voltage. The results also verify that μ-synthesis method is effective for the CPT technology.