▎ 摘　　要

NOVELTY - The standard leakage hole has a pressure-side metal knife-edge flange (1) that is hermetically connected to the side of the penetrating portion far away from the supporting portion . The vacuum-side metal knife-edge flange (3) is hermetically connected to a side of the supporting portion far away from the supporting portion. The permeation part includes a first PMMA layer (201) and a first graphene layer (202) are arranged in close contact with each other. The second graphene layer (203) is attached to a side of the first graphene layer far away from the first PMMA layer. The supporting portion is attached and arranged on a side of the permeable portion far away from the first PMMA layer. The supporting portion includes penetration holes (207). USE - Standard leakage hole of graphene/PMMA composite film. ADVANTAGE - A leakage gas is provided with stable leak rate for leak detection system, so as to perform leak rate test reliably. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a preparation method of standard leak hole of graphene/PMMA composite film. DESCRIPTION OF DRAWING(S) - The drawing shows a cross sectional view of a standard leakage hole of graphene/PMMA composite film. Pressure-side metal knife-edge flange (1) Vacuum-side metal knife-edge flange (3) First PMMA layer (201) First graphene layer (202) Second graphene layer (203) Penetration holes (207)