The invention relates to a biomimetic preparation method of a cerium dioxide/fluorinated-graphene oxide lubricating oil additive, and belongs to the fields of nano composite materials and self-lubricating materials. According to the method, fluorinated-graphene oxide self-prepared by a hydrothermal method is adopted as a raw material, and dopamine hydrochloride is utilized to biomimetically modifythe fluorinated-graphene oxide; and the prepared polydopamine/fluorinated-graphene oxide and Ce(NO3)3.6H2O are used as raw materials, ultrasonic dispersion is performed in a mixed solution of ethanoland water, and therefore the cerium dioxide/polydopamine/fluorinated-graphene oxide nano lubricating oil additive is prepared in a one-step in-situ manner by a hydrothermal method. According to the method provided by the invention, tribological test results show that the cerium dioxide/polydopamine/fluorinated-graphene oxide nano composite material prepared by the method has excellent wear-resistant friction-reducing effects and is an ideal nano lubricating oil additive.