Capacitive equipment in present power system is one of the equipment occupying large land area.With the development of VSC-HVDC

increasing the energy storage density and reducing the volume of capacitive equipment have become an urgent problem to be solved.The main way to improve the energy storage density of capacitor dielectrics is to increase the relative permittivity and breakdown field strength.And one of the methods to improve performance of dielectric material is to add inorganic Nano-materials into the organic polymer matrix.In this paper

the relative permittivity and DC breakdown filed strength for sample with different titanium oxide content are tested and the trap parameter of polypropylene/titanium oxide nanocomposite are compared and analyzed.It is shown by the result that adding of titanium oxide brings interfaces into the composite material

which has an effect on the dielectric properties of the material.The relative dielectric constant is the highest when the mass fraction of titanium oxide is 9%

which increases by 23.95% compared to the pure polypropylene.While

when the mass fraction titanium oxide is higher than 0.1%

the breakdown field strength decrease with the increase of titanium oxide content.