With the explosive growth of mobile traffic brought about by the emergence of mobile services such as virtual reality, and the actual needs of high-quality network services for user experience, the development of 5G mobile networks faces major challenges: ultra-large higher transmission bandwidth, lower transmission delay, lower unit construction and maintenance costs, and network reliability. The importance of prequel as the last mile of 5G network is constantly highlighted. 5G CRAN CWDM semi-active combines the low cost and rapid deployment of passive solutions with the safety and reliability of active solutions, eliminating the problem of uncontrollable dumb fiber resources and making a large number of fronthaul resources feasible. Management and control, and advanced optical communication and networking technology can not only meet the bandwidth and delay requirements of various new services, but also speed up the speed of business listing, while ensuring the reduction of unit construction and maintenance costs.