Theoretical analysis onthe performance of OXC nodes in which SOA is used as power equalization device ispresented. The power penalty of link with SOA is simulated; and then the impact of somefactors on system, including extinction ratio of transmitter, bit rate of signal,spontaneous noise factor of SOA, is discussed; finally the BER performance of cascaded OXCnodes with SOA-based equalization module is given. All these provide the theoreticalfoundation for the design of OXC nodes and the optical network.