Abstract: The development of polypropylene (PP)-based insulation materials used in the environmentally friendly and thermoplastic cables is one of the major trends in the field of high-voltage power transmission as part of the "carbon peak and carbon neutrality" strategy. In order to realize the localization of PP-based insulation materials used in the cables, we studied the mechanical and electrical properties of Sinopec's homopolymerized PP and PP alloy containing intrinsic elastomer, as well as their potential applications in environmentally friendly thermoplastic high-voltage cables. The results show that the PP alloy sample (no.4) has a higher content and smaller size of rubbery phase, as well as superior toughness and insulating properties, whereas its flexural modulus and dielectric loss should be addressed. In the future, chemical copolymerization and physical blending modifications will be further studied to optimize the content and size of rubber phase and reduce the catalyst residues, thus realizing the localization of PP-based insulation materials in the cables.