Based on the combination of simulation and experiment， the mechanical behavior of HMX-based granular in the mould pressing process was studied. The conventional charging model and jet charging model were constructed to elucidate the charge forming and crystal damage laws， and the molding pressure and density were experimentally verified. The results show that the increase of mould size leads to the decrease of stress transfer efficiency and significant increase of charge density gradient. The crystal damage rate of charges with diameter of 25 mm （13.94%） is nearly 3 times higher than that of charge with diameter of 10 mm （4.55%）. In the two-way pressing of jet charging， the symmetry of the load-displacement curves of the upper and lower indenters verifies the stress equilibrium transfer mechanism， and the simulation error of the side wall pressure （43.24 MPa） reveals the limitation of the spherical simplification of particles on the characterization of the friction effect. Through experimental verification， the simulation error of conventional charging density is less than 5%， and the prediction accuracy of axial pressure of jet charging is 94.3%， which confirms the reliability of the model.