Aiming at the problems of unstable running state and poor real-time monitoring effect of the traditional metal band sawing machine during processing, combined with digital twin technology, a real-time monitoring method of metal band sawing machine based on digital twin was proposed. A digital twin interconnected virtual entities and physical entities was built. A real-time monitoring system framework for the operating status of the band sawing machine was constructed based on the digital twin 5D model. After obtaining the actual operating data of the sawing machine, TWINCAT was used to simulate the PLC operation, and the data communication was carried out through the TCP/IP communication protocol of the XML file. Real-time data transmission was completed, and finally the data were uploaded to the MySQL database for storage. Thirdly, a scene roaming function that supported real-time 3D monitoring of the operating state of the sawing machine was developed, and a historical reproduction function that supported reappearing the historical operating state of the sawing machine was developed by querying historical operating data. Finally, the test verifies the real-time performance and effectiveness of the system.The results show that this system has good real-time performance and interaction.