The invention discloses a preparation method of a graphene nano-hole which is supported by a micropore, belonging to the fields of application of heavy ion beams and processing of films. A porous graphene composite material supported by the micropore is mainly characterized by comprising monolayer graphene, wherein the monolayer graphene is arranged on a polymer film; a nanoscale hole is formed in the graphene, overlapped and communicated with a cone-shaped hole of the polymer film. Through the preparation method, a graphene/polymer film composite structure is irradiated by using high-energy heavy ions; a hole with the diameter being several nanometers is formed in the graphene by using irradiation damage effect of the heavy ions; meanwhile, a columnar damage area is formed in the polymer film; then an irradiated area of a polymer is etched to form a cone-shaped nano-hole by using a chemical etching method; since the position of the graphene hole is overlapped and communicated with the position of the cone-shaped hole of the polymer, the graphene nano-hole which is supported by the micropore can be obtained. Due to the support effect of the polymer micropore, the graphene nano-hole is wide in application prospet in rectification of the ions, filtration and screening of the ions and detection of biological molecules.