Abstract: Polypropylene (PP), a semi-crystalline polymer widely used in film capacitors, has a crystalline structure that influences the electrical properties of the material, leading to variations in the energy storage performance of capacitors. Controlling the crystalline structure of PP to better regulate the electrical properties of PP films is key to enhancing the energy storage characteristics of capacitors. In this study, a series of uniaxially stretched polypropylene films with varying thicknesses were prepared. The differences in their crystalline morphology were characterized using polarizing microscopy, atomic force microscopy, two-dimensional X-ray scattering, and differential scanning calorimetry. Subsequent investigations were conducted on the trap parameters, DC breakdown strength, dielectric properties, and energy storage characteristics of the oriented PP films. The results indicate that thinner PP films not only improve the surface roughness of the films but also facilitate the formation of highly oriented shish-kebab fibrous crystalline structures. The highly oriented crystalline structure helps to optimize the trap distribution within the material, thereby promoting the dissipation of charges on the film's surface and enhancing the insulating performance of the material.