Abstract: With the rapid development of smart grid construction and the continuous expansion of customer needs, the "Four-network fusion" has become a hot concept and a key research object at the moment. The construction of the "Four Networks Convergence" project can improve the current situation of the city’s villages’ electric wires and cables being intertwined and disordered, reduce the cost of repeated construction, and open up a wider range of applications for power grid construction. It is the foundation for the future development of smart grids. This article introduces the core device "optical splitter" in the construction of "four-network integration", introduces the principle, type, manufacturing process, latest developments at home and abroad, and its application in the four-network integration construction. It provides a certain reference for the subsequent large-scale construction of "Four-network fusion".