3 d visualization of real-time monitoring and early warning system in compressed air equipment is semi physical simulation system for real-time 3d monitoring of field equipment used the 3d visualization of virtual simulation technology and PLC control technology. Real time data of all kinds of coal mining equipment transmission to the PLC system through the sensor, then used the technology of OPC storage of real-time data collected in the field in real time database, finally, according to the real-time data in the database the 3d simulation module control various devices in the virtual environment for action. VisualC++ and Eon as the development tools, used 3d data model and data structure suitable for the modeling and application of coal entity, geometric modeling, interactive 3d and color, light and material of virtual reality technology, it developed the real-time monitoring system of coalmine three-dimensional visualization.