With the fierce development of 5G communication technology, 5G base stations are being deployed on a large scale, and the deep coverage of base stations requires that the deployment location be closer to users. However, the traditional front-haul solution using fiber optic direct drive between DU and AAU has a series of problems such as tight pipeline resources, high cable cost, long construction period, and difficulty in capacity expansion. The semi-active device for the front axle of the 5G series is designed to solve the problems of the lack of cable resources, long construction period, and high cost due to the direct drive of the optical cable between DU-AAU in the 5G front-haul under the C-RAN architecture. The device adopts active WDM device on the DU side and a passive wavelength division multiplexer plus colored transceiver module on the AAU side to form a unified management and control front-haul network. It provides PC-side Web and client-side APP network management and high reliability 1+1 protective function. Realize the low-cost, high-reliability and fast deployment of 5G front-haul network construction for operators.