The invention provides a non-migrating POSS (polyhedral oligomeric silsesquioxane) grated anti-ageing agent and a preparation method thereof; active amino groups in an amine anti-ageing agent are allowed to react with active groups in single-active functional group POSS, the amine anti-ageing agent is chemically grafted to POSS molecules, and the POSS grafted anti-ageing agent is obtained. The novel anti-ageing agent of higher anti-oxidant property and higher anti-migrating property is provided for the ageing protection for rubber and other rubber elastomers, and anti-ageing efficiency is improved without affecting structural properties of rubber and other rubber elastomers.