A method for enzymatic preparation of fludarabine phosphate, comprising reaction of fludarabine with a high-energy phosphate compound under the action of deoxyribonucleic acid kinase. According to said method, acetate kinase and acetyl phosphate free acid or acetyl phosphate are also added. The technical problems present in the existing processes are successfully addressed by employing the enzymatic process to prepare the fludarabine phosphate. The usage of the high-energy phosphate compound is reduced by means of adding acetate kinase to recycle and regenerate a small amount of the high-energy phosphate compound, thereby reducing the generation of by-products having similar structures to the fludarabine phosphate, enhancing the operation convenience of purification steps in the industrial production of the fludarabine phosphate. The process is environment friendly, the reaction conditions are moderate, the cost is low, and the yield and the purity of the product obtained are high.