The invention relates to magnetic shock-absorption rubber and nanophase magnetic ferrite particles, specifically a process for preparing the nanophase magnetic ferrite particles and magnetic shock-absorption rubber prepared by using the nanophase magnetic ferrite particles. The invention is used for resolving the problems that the existing magnetic particles can not meet the physically mechanical property and magnetic shock-absorption effect of magnetic shock-absorption rubber and materials of the existing magnetic shock-absorption rubber are not properly selected and matched. 1.4-5.11g FeCl3, 6H2O, 1.75-6g FeSO4, 7H2O and 0.00025 mol polyethylene glycol with molecular weight of 400-10000 are added into 560ml distilled water, and further sodium hydroxide solution is added into the mixture, thereby nanophase magnetic ferrite particles which has certain shape and is coated by polyethylene glycol is achieved. The magnetic shock-absorption rubber is composed of components with percentage by weight of plantation rubber 15-60%, ethylene-propylene-diene monomer 15-60%, nanophase magnetic ferrite particles 5-50%, vulcanized agent 1-10%, vulcanizing activator 1-10%, vulcanization accelerator 1-10%, aging inhibitor 0.1-5% and reinforcing agent 10-40%.