Abstract: Traditional railway signal monitoring system has shortages such as low connectivity, lack of data sharing, and low intelligence. Combing with new technologies such as 4G wireless communication technology, big data and cloud computing, this paper introduced an intelligent railway signal monitoring system, which extended the intelligent extension of the existing signal monitoring system to the mobile terminal. The system is with the functions of fault prediction and diagnosis, alarm management and monitoring data inquiry. It has been applied in China Railway Chengdu Group Co. Ltd. The experimental results show that, the system ensures the real-time transmission of alarm signal of monitoring system, and improves the practicability and intelligentization of the monitoring system.