The invention provides a benzofuran [2,3-b] pyrazine derivative as well as application thereof in an organic electric fluorescent device. The chemical structural formula of the benzofuran [2,3-b] pyrazine derivative is as shown in the specification. In the formula, A is carbazole at different sites and a derivative of carbazole, triphenylamine at different sites and a derivative of triphenylamine, spirofluorene closed loop triphenylamine at different sites and a derivative of spirofluorene closed loop triphenylamine, spirofluorene at different sites and a derivative of spirofluorene, or acridine at different sites and a derivative of acridine. The benzofuran [2,3-b] pyrazine derivative provided by the invention can be used as a light emitting body to prepare the organic electric fluorescent device, an efficient electroluminescence property can be achieved, the maximum light emitting efficiency can be up to 11.5 Cantera per ampere, and the external quantum efficiency is up to 4.44%, which is approximate to the theoretical boundary value of 5% of a fluorescent material as the light emitting body in the organic electric fluorescent device.