The CWDM OADM is a kind of WDM technology based on TFF, which has a variety of package sizes and wavelengths. In the transmission optical path, OADM module can upload and download WDM signals without photoelectric conversion. It is one of the important equipment of key nodes in WDM optical network. Adopting OADM module can give play to its flexible networking, easy network upgrade and scale expansion, and is widely used in LAN, MAN and other fields.