Non-destructive identification of entanglement is very important in quantum information processing. A scheme is proposed which constructs a controlled phase shifter (CPS) gate via the cavity input-output process. The CPS gate can be used to construct a parity analyzer (PA) with homodyne detection technology. Moreover, it uses the PAs, combined with some other operations, to construct the non-destructive atomic Bell state and GHZ state analyzers. The scheme has two advantages. It uses the coherent light and homodyne detection, which are much easier to be implemented than single photon source and single photon detection. The atomic Bell state and GHZ state analyzers constructed are non-destructive. All the methods and techniques used in this scheme are achievable in the present experiment.