▎ 摘　　要

NOVELTY - Preparation of a metastable graphene film involves heating a graphene oxide film to 1800-2100° C at a heating rate of 100° C/minute or less, maintaining the temperature for 4-16 hours to reduce defects of the graphene oxide film to 0.5% or less, maintaining a non-AB structure, heating to 2300-2400° C at a heating rate of 60° C/minute or more, and cooling to 1800° C or less within 10 minutes. USE - Preparation of metastable graphene film used for high-speed photoelectric device and magnetic device. ADVANTAGE - The method produces metastable graphene film having excellent heat stability, electroconductivity, light-absorption property, and magnetoresistive effect. The method is high in reliability, simple in technology, and economical.