The invention provides a frequency bifurcation characteristic based inductive power transfer (IPT) system parameter optimization method. According to the method, a primary side compensation capacitance initial value is obtained through an alternating current impedance analysis method, then, a primary side compensation capacitance optimization value Cp is obtained according to iterative operation and computer simulation, and an IPT system soft switch frequency bifurcation graph is a standard furcation bifurcation graph, namely, a frequency invariant zone exists. Therefore, as long as the load RL of the IPT system is guaranteed not to exceed the load range in the frequency invariant zone, the soft switch frequency of the IPT system can be guaranteed to be invariant. The optimization method is simple, direct and effective, and can rapidly acquire the primary side compensation capacitance optimization value Cp.