It is challenging to determine the damage type or mechanism under different stress states because of the high degree of disorder of the microdamage inside the metal material. The application of many nondestructive testing methods makes the realization of this subject possible. In this work, acoustic emission (AE) was implemented to test the microdamage evolution process of two aluminum alloy materials (1060 and 6063). Two types of notched specimens (shear and tensile) had been used. AE signatures acquired during testing were used to construct the multicomponent variate DA damage matrix. The multicomponent variate DA matrix and probabilistic entropy were applied to analyze the diversity of the microdamage evolution of different materials under different stress states. And the fracture surfaces were observed by a scanning electron microscope (SEM) to verify the correctness of the analysis results. Consequently, the probabilistic entropy results show that AE data characterization can effectively distinguish the significant difference of microdamage evolution of the aluminum alloys under two kinds of stress state. It is also shown that the microdamage evolution mechanism represented by the probabilistic entropy of aluminum alloys under the same stress state is consistent.