Deep-sea mining activities have lately attracted growing interest. Recent research has led to the development of a hydraulic–mechanical hybrid vertical lifting system for deep-sea mining. Predicting the resistance of vertical plug flow in this system is critical for its engineering design. In this paper, an analytical model was developed to determine the resistance of vertical plug flow in a hydraulic–mechanical hybrid vertical lifting system in the presence of coarse particles. A recent model of the stress transmission ratio for pneumatic plug flow was verified and applied to the proposed model of resistance. In addition, it is considered that the co-existence of turbulent and laminar flows in the fluid flowing through the particles provides the necessary pressure gradient. A test setup was built to measure the resistance of vertical plug flow with/without water, along with varying particle diameters, plug lengths, and lifting speeds. Comparisons between the predictions of the analytical model and experimental measurements showed that they deviated by less than 13.6% on average. This shows that the proposed analytical model can be used to predict the resistance of vertical plug flow involving coarse particles.@en