GaN LED has got an extensive application for its life, efficiency, environmental protection and other advantages. The life question has been the core question, which limits the application of the GaN LED. In order to research the GaN LED aging process, calculate GaN LED physical parameters, such as life time and so on, the aging principle of deep level GaN LED defects and the non-radiation recombination centers increasing are analyzed. And according to the principle, we analyze the physical theory of GaN LED aging process, and finally establish an aging mathematical model for a GaN LED. Meanwhile, through a calculation of a set of practical GaN LED big stress aging experiment data with the aging mathematical model, a test method and mathematics calculation method of the life time are established, and finally we calculate the experimental GaN LED life value. Compared with the traditional Allen News model, the GaN LED aging mathematical model has many advantages such as strong pertinence, obvious physical meaning and more accurate life prediction, and has a very good application value.