This work aims to study the effects of length, thickness and different viscosity liquid of film on tearing of flexitank. CATIA software was used to establish a flexitank model with different lengths, thicknesses and different liquid viscosity. The flexitank was simulated under static and dynamic conditions with the ABAQUS soft. After simulation analysis, data on stress, strain, strain energy density and maximum tear energy of the flexitank were obtained. After selecting the best solution by orthogonal analysis, the maximum strain under static was 0.064 77, the maximum strain energy density was 0.1928×10-3 J/mm3, the maximum tear energy was 0.1868 J/mm3, and the maximum strain under dynamic was 0.063 04. The strain energy density was 0.1885×10-3 J/mm3 and the maximum tear energy was 0.1828 J/mm3. The tear of the PE film with lower crystallinity is mainly related to the maximum tearing energy of the film. Increasing the length of the flexitank can reduce the maximum tearing energy at the top of the PE layer and improve the safety performance of the flexitank. The tearing at the top of the PE layer of the flexitank under dynamic conditions is the main cause of damage to the flexitank.