The principle of property improvement for polymer by using rigid nanometric particles has been presented,and analysis of property-improving mechanism for polymer material by using nmSiO_2/siloxane(silicone rubber) has been emphasized.Taking solvent gasoline No.120 as dispersing agent,a kind of compounded material has been made through co-mixing method to obtain nmSiO_2-vinyl siloxane with addition of hydrogen-containg siloxane for vulcanizing reaction.The agglomerative structure of the said material has been analyzed and studied by using AJ-Ⅲ_a atom-powered microscope,and its mechanical property has been tested.Results show that the elastic modulus of material has been enhanced by 15.4%,the tensile strength increased by 19.4%,and the specific elongation of breaking increased by 30%after improving property with siloxane rubber.Adopting property-improved siloxane polymer material to coat the optical fibre Bragg grating pressure sensor,the coupling behavior between coated material and optical fibre Bragg grating