NOVELTY - The method comprises providing a carbon nanotube structure on a surface (201) of a metal substrate (20), implanting carbon ions into the metal substrate through strip-shaped gaps (412), and annealing the metal substrate to obtain the strip shaped graphene layer. The carbon nanotube structure comprises drawn carbon nanotube films comprising carbon nanotube segments (411) each of which is parallel to each other and separated from each other by the strip-shaped gaps. The metal substrate has a thickness of 100 nm to 100 mu m. A width of the strip-shaped gaps is 20-80 nm.    USE - The method is useful for making a strip shaped graphene layer (claimed), which is useful in semiconductor devices such as sensors, thin film transistors and solar cells.    ADVANTAGE - The method is capable of efficiently and economically making the strip shaped graphene layer with excellent electrical and thermal properties.    DETAILED DESCRIPTION - The method comprises providing a carbon nanotube structure on a surface (201) of a metal substrate (20), implanting carbon ions into the metal substrate through strip-shaped gaps (412), and annealing the metal substrate to obtain the strip shaped graphene layer. The carbon nanotube structure comprises drawn carbon nanotube films comprising carbon nanotube segments (411) each of which is parallel to each other and separated from each other by the strip-shaped gaps. The metal substrate has a thickness of 100 nm to 100 mu m. A width of the strip-shaped gaps is 20-80 nm. The drawn carbon nanotube films are stacked with each other. Each drawn carbon nanotube film is made by steps consisting of: providing a carbon nanotube array; selecting a carbon nanotube segment having a predetermined width from the carbon nanotube array; and pulling the carbon nanotube segment at a uniform speed to form uniform drawn carbon nanotube films. The carbon ions are accelerated in an electrical field and impacted into the metal substrate through the strip-shaped gaps of the carbon nanotube structure. Strip carbon ion implanted zones: are formed on the surface of the metal substrate and exposed out of the carbon nanotube structure via the strip-shaped gaps; and have the same pattern as the strip-shaped gaps. A carbon ion implantation energy of the electrical field is 10-50 KeV, and a carbon ion implantation dose is 1x 1015/cm2 to 1x 1017/cm2. An angle between an accelerating direction of the carbon ions and the surface of the metal substrate is 10-90 degrees . The annealing step comprises: placing the metal substrate in a reacting chamber; heating the metal substrate to a predetermined temperature for a predetermined period; and cooling the metal substrate to a room temperature. The annealing step is processed in a vacuum environment or an inert gas environment. The heating temperature is 550-1500 degrees C, and the heating period is 20-60 minutes. The carbon nanotube structure is removed from the metal substrate.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic cross-sectional view of a method for making a strip shaped graphene layer.    Metal substrate (20)    Strip carbon ions implanted zones (100)    Surface of the substrate (201)    Carbon nanotube segments (411)    Strip-shaped gap. (412)