▎ 摘　　要

NOVELTY - Method for preparing a magnetic locating marking material, involves (i) generating graphene by hummers method from a graphite powder, adding to the DEG solution, and ultrasonically processing to obtain a graphene solution, (ii) preparing urea, ferric chloride and ferrous sulfate into a mixed solution, and (iii) hydrolyzing the graphene solution and the mixed solution at a certain temperature for a period of time under reflux conditions to obtain the product. USE - The method is used for preparing the marking material for digestive tract lesions. ADVANTAGE - The method provides the marking material which has stronger stability, magnetic properties and physical and chemical properties than conventional magnetic nanomaterials, and has better biosafety when applied to living bodies, and is not easy to be biodegraded.