The invention relates to a method of manufacturing a phase-change memory. The method includes the following steps that: a structure is formed, wherein the structure comprises bottom electrodes, a dielectric layer on the bottom electrode, an isolation layer which is arranged on the dielectric layer and has openings passing through the isolation layer, and a polysilicon layer which is arranged in the openings; first holes and second holes are formed, wherein the first holes and second holes respectively pass through the polysilicon layer and the dielectric layer, and the second holes are locatedbelow the first holes; a protective layer is formed in the first holes and the second holes and above the polysilicon layer; a chemical mechanical polishing process, or a dry etching process and a chemical mechanical polishing process are performed, so as to remove part of the protective layer, the isolation layer and the polysilicon layer, expose the dielectric layer, and preserve the protectivelayer in the second holes; the protective layer in the second holes is removed so as to expose the second holes; and a heating material is deposited into the second holes. With the method adopted, danger caused by using a tetramethylammonium hydroxide solution can be avoided, and hole damage in the dielectric layer can be avoided, and therefore, the holes have good dimensional stability.