The invention discloses a universal non-valatile write-once read-many memory and a preparation method thereof, and belongs to the field of resistive random access memories. The universal non-valatile write-once read-many memory comprises a substrate, a bottom electrode, a memory medium layer and a top electrode are arranged on the substrate in sequence, and the memory medium layer is a pure insulating polymer layer. The invention discloses the preparation method of the memory. The raw materials adopted in the method are easy to obtain, the cost is low, the memory prepared by using the method has the non-valatile write-once read-many memory characteristics and has the advantages of being low in write voltage, high in switch ratio, low in misreading rate and high in stability.