During the transfer process for coal with the utilization of mining conveyor belts, large pieces of coal often affect the safety of transportation, so real-time monitoring of the transport process in lump coal is essential. Therefore, a real-time monitoring method GSB YOLOv5 is proposed. Firstly, the dataset's contrast is enhanced by adaptive histogram equalization, while its richness is improved by combining Mosaic multi-data enhancement. Secondly, it proposes the utilization of Ghost Net, which is a neural network with low computational requirements for lightweight extraction and fusion of features. This approach effectively minimizes the model computation. In addition, the combination of Squeeze-Excitation mechanism improves the extraction of model's feature capabilities. Finally, a feature pyramid with weighted bidirectional is employed to accomplish multi-source information fusion by effectively merging features at varying resolutions. The experimental findings demonstrate that the enhanced GSB YOLOv5 algorithm achieves a 35.256% significant reduction in network layers, while it has substantial reductions of 63.023% and 68.582% in parameters and floating point operations, respectively. Furthermore, the compressed model size is decreased from 92.7MB to 34.4MB. In addition, there are improvements of 1.421% and 1.460% in the detection precision and recall rate of the model, respectively, while the detection efficiency of the real-time has a significant boost from 68.34 FPS to 107.91 FPS. Automatic, fast and high precision monitoring of lump coal objects on conveyor belts in underground coal mines can be realized.