The invention relates to a method for preparing a phase change memory with a vertical structure, and belongs to the technical field of nano-electronic and nano-optoelectronic devices. The method comprises the steps of substrate preparing, thermal protective layer plating, thin layer plating, template laying, ion etching, template removing, thermal insulation layer plating, polishing and planishing, photoengraving and corroding, thermal insulation layer re-plating, re-polishing and planishing, and electrode manufacturing. The method adopts nano-array phase change material as a carrier for information storage, improves the thermal efficiency of the phase change active region through introducing a proper dielectric layer between the electrode and the phase change material, ensures that the operating current and the power consumption of the memory device are effectively reduced, and has the advantages of simple process and low cost, thereby providing the foundation for the commercial memory which is suitable for PCRAM.