▎ 摘　　要

NOVELTY - Preparing graphene film involves mixing 1 pts. wt. of graphene or graphene oxide and 5-150 pts. wt. solvent after ultrasonic dispersing the graphene or graphene oxide into a dispersion liquid. The graphene or graphene oxide dispersion liquid is added to extrusion device at a rate of 1-1000 ml/h to obtain die. The obtained die is solidified at 10-80 degrees C for 1-100 seconds to obtain solidified graphene or graphene oxide gel film. The obtained gel film is dried and then the dried gel film is kept in high temperature furnace filled with inert gas at a heating speed of 1-5 degrees C per minute at 3000 degrees C. USE - Method for preparing graphene film (claimed). ADVANTAGE - The method enables to prepare graphene in simple, eco-friendly and energy saving manner, with high conductivity, high tensile strength and excellent thermal performance, and has improved the cooling effect of electronic products. DETAILED DESCRIPTION - Preparing graphene film involves mixing 1 pts. wt. of graphene or graphene oxide and 5-150 pts. wt. solvent after ultrasonic dispersing the graphene or graphene oxide into a dispersion liquid. The graphene or graphene oxide dispersion liquid is added to extrusion device at a rate of 1-1000 ml/h to obtain die. The obtained die is solidified at 10-80 degrees C for 1-100 seconds to obtain solidified graphene or graphene oxide gel film. The obtained gel film is dried and then the dried gel film is kept in high temperature furnace filled with inert gas at a heating speed of 1-5 degrees C per minute at 3000 degrees C. The heated material is cooled naturally to obtain a graphene film. The solvent is selected from water, methyl alcohol, ethyl alcohol, N-methylpyrrolidone, acetone, dimethyl sulfoxide, pyridine, dioxane, N,N-dimethylformamide, N,N-dimethyl acetamide, tetrahydrofuran, butanone or diethylene glycol.