The invention discloses a petrochemical unattended loading and unloading line digital twinning intelligent monitoring system. The system comprises a physical entity, a digital twinning body, an intelligent gateway, a cloud server, a network switch and a client interaction terminal. A digital twinning model is established according to an actual petrochemical loading and unloading line, a loading and unloading line digital twinning body is constructed, the twinning body acquires equipment operation state and process real-time data through an intelligent gateway, twinning data are updated through data fusion, and perception analysis, iterative optimization and decision control are performed by adopting a neural network deep learning algorithm. And meanwhile, the equipment operation state is monitored in real time based on the digital twinning model, parameter control optimization is conducted on loading and unloading operation, and fault prediction and maintenance are conducted on the whole loading and unloading line. The problems that an existing loading and unloading line is low in efficiency, low in visualization degree, poor in man-machine interaction capacity, weak in equipment coordination capacity and the like are solved, and the monitoring real-time performance, the operation efficiency and the equipment safety of the loading and unloading line are improved.