A tubular soft bag covering a rigid tube, known as a coring system, is a key tool in deep lunar soil coring. The dynamic performance of the coring system is of critical importance, largely determining the quality and efficiency of the lunar soil coring. The main contribution of this study focuses on analyzing the mechanism of the force dragging the soft bag in the dynamic process of the simulated lunar soil coring analytically, numerically and experimentally. By adopting the combination of mechanism analysis and experimental study, a novel mechanical model of the dragging force is founded. Using this mechanical model, the process of deep simulated lunar soil coring can be divided into three stages. Besides, the whole dynamic process of the simulated lunar soil coring is simulated by coupling Finite Element (FE) and Smoothed Particle Hydrodynamics (SPH) methods using the nonlinear finite element code LS-DYNA. The numerical simulation results show that the flexible tube coring system provides advantageous performance, and its dynamic performance is in accordance with the theoretical analysis. To further evidence the effectiveness and accuracy of the mechanical model and the numerical simulation, a special test-bed for soil coring is built and experiments are conducted. It can be found that results obtained from these three methods are in good agreement. The findings from this study can provide a directive and practical guidance to improve the safety and reliability of the deep soil coring system. (C) 2018 Elsevier B.V. All rights reserved.