In the 5G system fronthaul of mobile communication technology, optical modules play a key role. On the one hand, it meets the needs of high-speed data transmission, supports long-distance transmission, is not subject to electromagnetic interference, has a long life, and improves system reliability. At the same time, it can adapt to different network architectures, such as fiber direct drive, passive wavelength division multiplexing, and active WDM. On the other hand, optical modules facilitate network upgrades and expansions. With the development of 5G technology, network upgrades can be achieved by replacing higher-performance modules or increasing the number of modules, providing good support for the long-term development of 5G systems.