Abstract: To cope with the bottleneck of carrying bandwidth and transmission rate of the existing train-ground wireless network in urban rail transit, a study is made on how to utilize the advantages of 5G mobile networks and a 5G-mobile-network-based collaborative transmission scheme was proposed in combination with the construction results of the existing LTE wireless network in urban rail transit, which provides a feasible solution to the application of 5G mobile networks in urban rail train-ground wireless transmission services and realizes on-line distribution of vehicle PIS 's multimedia contents and automatic download of vehicle surveillance video and onboard logs, effectively improving the automation and intelligent level of onboard operation services.