A reconfigurable optical add-drop multiplexer (OADM) based on F-P cavity and piezoelectric translator is proposed. In this structure, the displacement of F-P cavity can be controlled by piezoelectric translator. The OADM can add/drop one of the multi input channels or pass the channel directly by adjusting the electric voltage of the piezoelectric translator. The channel isolation is more than 30dB. Crosstalk, including inter-band crosstalk and intra-band crosstalk, in F-P filter based OADM are analyzed and calculated in this paper.