Abstract: This study focus on drop test reliability of flexible packaging bags during transportation and usage, numerical simulation was employed to investigate their mechanical characteristics. Firstly, a pre-filling simulation is conducted using the packaging design system to obtain the precise bag configuration after filling. Secondly, Nonlinear material parameters were determined by material tests, Finally, based on the explicit dynamic finite element method combined with SPH theory, the non-Newtonian fluid behavior of the liquid contents is analyzed, and the drop characteristics and failure patterns of different bags configurations are studied. The study showed that accurate assessment for drop test reliability could assess by numerical method combining explicit dynamics analysis and pre-filling simulation. The aspect ratio of the bag and the dimensions of the sealed edges significantly influence the failure mode and placement stability. The study methodology provides an effective approach for the configuration design and optimization of flexible packaging bags.