In the atomic clocks based on the Ramsey process, the free evolution time cannot be very long which is limited by the coherent time of atoms and the phase noise of crystal oscillation. The non-destruction detection method with a large-detuning light is proposed. The atom phase data are obtained with this method and fed back to the microwave phase, which contributes to the realization of the atomic phase feedback and the effective prolonging of the free evolution time. The feasibility of such a periodical feedback is verified by the theory and experiment, respectively.