On the basis of different light guiding principles, hollow-core microstructure fibers can be divided into hollow-core photonic band gap fibers and hollow-core anti-resonant fibers. For these two types of fibers, scattering loss caused by the roughness of the inner wall of the air hole is one of the sources of loss. Scattering loss is the main source of loss in hollow-core photonic bandgap fibers. In hollow-core anti-resonant fibers, scattering loss is also one of the important reasons for loss during operation in the short-wavelength region. To reduce the scattering loss of hollow-core microstructure optical fibers, in-depth research on the roughness of the inner wall of the air hole is necessary. Therefore, in this paper, research progress on the relevant theory, measurement technologies, and suppression methods for the roughness of the inner wall of the air hole in hollow-core microstructure optical fibers are described. Further, relevant theory and experimental results are summarized, and important future research directions are suggested.