The invention discloses a method for precisely representing a gamma irradiation carbon fiber microstructure. The method comprises the following steps that 1, gamma-ray irradiation carbon fibers are divided into three microcells, namely, an outer surface, a secondary surface layer and a core part along the radial cross section; 2, the chemical structure of the outer surface of the carbon fibers is represented through the X-ray photoelectron spectroscopy-argon ion gun sputtering coupling technique, and atoms and crystal structures of the secondary surface layer and core part of the fibers are represented through the section Raman fixed point scanning technology. The gamma-ray irradiation carbon fibers are divided into the three microcells, namely, the outer surface, the secondary surface layer and the core part along the radial cross section, different testing means are combined for representing, and the problem that the microstructures of different regions of the gamma-ray irradiation carbon fibers cannot be accurately obtained is solved.