Abstract: Polypropylene(PP) insulation material has the advantages of excellent insulation performance, no cross-linking and melting reuse, which is an important development direction of environment-friendly HVDC cable insulation. The contradiction between electrical and mechanical properties of polypropylene based insulation materials is difficult to coordinate control, which is the main bottleneck of domestic high voltage DC cable polypropylene insulation. From the aggregate structure of polypropylene insulation, the aggregate structure of polypropylene insulation and its characterization methods are introduced, with a brief summary of the research progress of blending and copolymerization, nucleating agent addition and crystallization temperature control in regulating the aggregate structure and macro properties of polypropylene, and the influence of different control methods on the electrical and mechanical properties of polypropylene insulation for HVDC cables are discussed. The results show that β nucleating agent can inhibit the injection and accumulation of space charge in polypropylene insulation, improve the breakdown field strength, and significantly improve its impact resistance. Appropriate crystallization temperature can improve the crystallinity of polypropylene, control the spherulite size, and improve the electrical and mechanical properties of insulation. Finally, based on the actual operation condition of HVDC cable, the improvement method and application prospect of aggregate state control of polypropylene insulation material are analyzed and prospected.