Based on a non-linear inductive power transfer (IPT) system with π–type resonant network, we applied generalized state space averaging (GSSA) method to achieve frequency domain resolving of time-domain state variables, then real and imaginary parts of the low order fourier coefficients as new variables, approximately, built-up a linear time-invariant system. Comprehensive consideration of parameter perturbation in medium and low frequency as well as uncertainty of un-modeling part in high frequency, an output feedback H∞ robust controller with mixed sensitivity was designed. The weighted functions for multi-objective optimization were adjusted to obtain tracking control without steady-state error and robustness analysis of the load output voltage. The simulation results show that using robust controller, H∞ norm for the closed-loop system’s transfer function reaches to the performance index which is less than 1. In the cases of load parameter perturbation and input voltage disturbance, the system realizes the tracking robust control without steady-state error for the load output voltage, and simulation results verify the feasibility of the proposal.