Abstract: In view of the difficulty in promoting the information based work due to the communication quality in the current railway engineering construction stage, this paper analyzed the advantages of smart construction site based on 5G technology in the railway construction industry, put forward the application strategy of 5G technology in the current railway construction industry, and explained the specific application of 5G technology in six aspects of personnel positioning, material management, safety management, quality control, environmental monitoring and emergency rescue in railway engineering construction. It provided reference for the deepening application of 5G technology in the process of railway smart construction, promoting the intelligent, efficient and green collaborative development of railway engineering construction process, and improving the level of railway engineering intelligent construction.