The invention discloses an aminophosphate functionalized ionic liquid and a preparation method and application thereof. The aminophosphate functionalized ionic liquid is characterized in that imidazole is taken as a cationic substrate of an ionic liquid, and aminophosphate is introduced onto the side chain of imidazole to realize synthesis of the aminophosphate functionalized ionic liquid. The phosphate functional group in the functionalized ionic liquid is linked with an imidazolium cation through an aminoalkyl chain, and phosphate and amino have coordination effects on uranyl metal ions, so that the problem of low uranyl extraction efficiency of the conventional TBP-functionalized ionic liquid is solved. The aminophosphate functionalized ionic liquid provided by the invention can serve as an efficient extraction agent to be used in the field of extraction and spent fuel after-treatment of the uranyl metal ions, and has the advantages that the extraction efficiency is high, and one-time uranyl extraction rate can be up to 99.88%.