Our brain waves consist of a lot of nonlinear characteristics. Holo-Hilbert cross-frequency phase clustering (HHCFPC) is a cross-frequency coupling connectivity analysis based on the nonlinear Holo-Hilbert Spectral Analysis (HHSA) method. It is achieved by clustering the vectors of "phase difference" between the phase of a first layer IMF (obtained by HHSA) from one EEG channelthe phase of a second layer IMF from the other EEG channel. The results of HHCFPC can be used as a guide to optimize the parameters (e.g. frequency,frequencydepth of AM) of non-invasive brain stimulations.