The invention relates to an additive capable of improving the dynamic mechanical property of rubber as well as a preparation and application of the additive. The additive has a chemical structural formula as shown in the specification, wherein n is an oxidation state of a metal element M and is equal to 2, 3 or 4; A is one of oxygen, sulfur, carbon, nitrogen, phosphorus and silicon, and x is larger than or equal to 0 and is smaller than or equal to 10; B is one of oxygen, sulfur, carbon, nitrogen, phosphorus and silicon, and y is larger than or equal to 0 and is smaller than or equal to 10; (AxBy)m shows that atoms are connected by chemical bonds, and x and y are not zero at the same time; m is larger than or equal to 0 and is smaller than or equal to 10; z is smaller than or equal to 50;a and b are positive integers; R1 and R2 are aliphatic chains, alicyclic hydrocarbons or aromatic compounds of which the carbon atom numbers range from 0 to 50; and R3, R4, R6 and R8 are aliphatic chains or alicyclic hydrocarbons of which the carbon atom numbers range from 0 to 50, and R5 and R7 are aromatic compounds. When the additive prepared by using the preparation method is used for preparing rubber, the dynamic mechanical property of the rubber is improved, and parts of rubber compositions containing the rubber additive have improved Shore hardness and elasticity modulus and reduced loss factors.