The invention discloses a preparation method of a graphene oxide field emission flat plate display instrument. The method comprises the following steps: coating a layer of photoresist on a plane substrate; patterning the photoresist, and exposing an area needing preparation of a field emission point on the substrate; plating a metal film; setting nickel nanometer particles on the metal film through magnetic field assistance; performing heat processing in a vacuum furnace; depositing a layer of graphene oxide on the surface of a sample; removing the residual photoresist to obtain a field emission lattice; performing wiring on the field emission lattice; placing an ITO glass sheet plated with fluorescent powder in parallel above the sample, and preparing a field emission flat plate module, wherein the sample and glass are spaced at a certain interval by use of an insulating material; and forming a peripheral circuit by use of a single-chip microcomputer and a shift register to realize screen display. The electron source of the flat plate display instrument prepared by use of the method is a novel field emitter structure, and the flat plate display instrument has the advantages of stable emission currents, small driving voltage, high electron emission efficiency and the like.