Abstract: This paper designed a remote version management system for metro train onboard software to address issues such as low efficiency of on-train software upgrades and difficulty in meeting customer needs in the urban rail transit industry. It elaborated on the architecture of the system, as well as functions such as data version management and automatic network status detection and upgrade, and divided the upgrade process into two stages: pre-download during daytime operation and installation during nighttime maintenance. The system applied technologies such as dynamic bandwidth regulation, breakpoint continuation, and data verification to ensure the uninterrupted operation of metro trains and the integrity and security of data transmission. Theoretical analysis and laboratory simulation tests show that the system is safe, reliable, easy to manage, and saves maintenance time, thus providing an efficient and reliable software maintenance solution for fully automated operation systems.