In order to reduce the risk of manual overhaul, improve the construction efficiency, and humanely assist the TBM driver to decide whether the cutting tools need to be changed or not, it is of great significance to realize the visual management of the scrape cutter abrasion. The resistor array type wear sensor is introduced; the working mechanism of the sensor (signal transmission and realtime display on human machine interface (HMI)) is presented; and a realtime wear monitoring system for scrape cutters and tearing cutters is studied in detail. Furthermore, the system was applied to a metro project of Beijing New Airport Line. The results show that the wear sensor is of high accuracy and versatility, and abrasion magnitude could be displayed on the HMI in real time, so as to significantly improve the shield tunneling efficiency. 