Abstract: In order to improve the effect of metro vehicle fault monitoring,a metro vehicle fault monitoring system based on big data technology is proposed. The system includes the modules of early warning monitoring,alarm management,fault record query and statistics,auxiliary decision-making,diagnosis report,equipment management,standard management and system maintenance,and so on. After the data is collected,K-means cluster analysis method and Apriori algorithm association rule are used to realize the correlation analysis between the collected data parameters and the equipment fault parameters. The fault with the largest membership degree is selected as the fault diagnosis result of the equipment.