Passive WDM technology is the main technology used in 5 G forward transmission at this stage. As the speed of 5 G forward transmission is as high as 25 Gbit/s
dispersion becomes the main factor affecting. This paper introduces the technical principle of passive WDM in forward transmission and its wavelength assignment in common models. It studies the TDP index of optical module and analyzes its infl uence in 5 G forward transmission. Finally
it analyses the transmission index of optical fi ber link and proposes the suggestions of passive WDM technology in 5 G forward transmission.