Non-Fourier heat transfer model cannot be solved by conventional method of separating of variables. A conventional method of separating variables is developed. Fourier model, Cattaneo-Vernotte (C-V) model and dual phase lag (DPL) model are solved by the method. Differences of temperature fields calculated with three models are compared. Temperature fluctuation in C-V model and DPL model is studied. And relation between temperature fluctuation velocity and time lag of heat flux is studied.