The invention belongs to the technical field of graphene modification, in particular to a method and a device for surface modification of graphene oxide. The device comprises a gas path, a plasma reactor and a circuit, wherein the gas path comprises a gas storage bottle and a gas chamber, and the gas storage bottle is communicated with the gas chamber; the plasma reactor consists of seven atmosphere plasma jet basic units, and each basic unit consists of a hollow metal needle electrode, a hollow quartz tube and an annular electrode; one end of the hollow metal needle electrode is insert into the hollow quartz tube, and the other end of the hollow metal needle electrode is communicated with the gas chamber; the annular electrode is wound at the lower part of the hollow quartz tube; and thecircuit is connected with the plasma reactor. The device is not only safe, reliable and low in power consumption, but also the generated plasma jet has high electron density, low temperature, long length and large area, and is very suitable for efficiently and uniformly processing graphene oxide, a two-dimensional carbon nano material with the characteristics of large area and extremely small thickness.