Abstract: High-energy radiation can lead to chemical changes such as cross-linking and degradation of energy storage dielectric of capacitors, which will affect the electrical performance and application of the capacitor. Taking the typical shish-kebab structure of biaxially oriented polypropylene (BOPP) film as the object, the effects of accumulated γ irradiation dose D on the molecular chain structure and crystallization characteristics are studied, and the irradiation degradation model is established. The results show that when D < 10 kGy, irradiation crosslinking and degradation reactions occur simultaneously to the same extent, and the crystallinity and the content of molecules with high molecular weight do not change significantly. When D≥10 kGy, the irradiation degradation reaction is dominant, the shish structure is gradually destroyed, and the crystallinity and the content of molecules with high molecular weight decrease gradually. When D=1 000 kGy, the shish-kebab structure is almost completely destroyed, and there is mainly lamellar and amorphous region in the film. The model describes the degradation process of shish-kebab structure when applying γ irradiation, providing a reference for the irradiation aging mechanism of polymer crystal structure.