Abstract: Based on GB/T 33047.2—2021 and GB/T 11026.2—2012, thermal degradation process of two typical ethylene propylene diene monomer (EPDM) insulation materials used in cables was studied by thermal analysis technology, and thermal degradation activation energy was calculated at weight loss of 5%. Then, based on GB/T 11026.3—2017, GB/T 11026.9—2016, and GB/T 11026.10—2019, combined with the selection of high temperature points in conventional aging methods and Arrhenius empirical formulas, thermal aging life equations of the two materials were established, and the service life was calculated at an extreme service temperature of 90 ℃. Finally, shortcomings of rapid analysis were discussed and future development direction was also pointed out.