Based on two core technology (positioning function, transfer function) and four core modules (equipment monitoring, operation monitoring, version monitoring, job monitoring) of LMD (LKJ (L) monitor and management (M) device (D)) system. System basic structure, function and application of LMD system, and the relationship between the system and vehicle equipment production management platform were elaborated, and the information security measures taken by the system was described. The system had been applied in several railway bureaus, which reduced the accident rate.