A new brush coating process technology is developed to manufacture high-temperature co-cured damping film. The visco-elastic material was firstly dissolved into a volatilizable organic solvent, and then the viscous mixture was coated on surface of composite prepreg. According to the cure curves of T300/QY8911, the specimens of embedded co-cured composite structure were made. Finally, the modal analysis experiences of the specimens manufactured by the membrane forming process and brush coating process were completed and the curve of the low order modes parameters with respect to damping film thickness was obtained. The results show that the specimens manufactured by brush coating process have better damping performance. This investigation will provide an important foundation for the further exploring design theory and manufacturing technology of composite material structure with lightweight and high damping.