Aviation composite materials, as the key technology of aircraft lightweighting, are widely used in the field of aviation. However, under the new situation of large-scale, complex and intelligent development, there is an urgent need for breakthroughs in non-contact multi-damage rapid detection technology for composite materials. Based on this, this paper proposes a fast multi-damage imaging method for composite materials based on Hilbert marginal spectrum and air-coupled ultrasonic guided wave composite path cross-imaging. First, the propagation characteristics of the guided waves in the composite plate are analyzed through numerical simulation to determine the optimal incidence angle of the ultrasonic probe and the propagation modes of the guided waves in the composite plate; second, in order to solve the problem of artifacts that may easily appear in the multi-damage imaging, the air-coupled ultrasonic guided waves are used for scanning in double orthogonal directions, and the signals of the guided waves are captured when they propagate along the direction of composite fiber layups at 0°,45°,90°and 135°; Then, the fully integrated empirical mode decomposition and adaptive noise algorithm combined with energy entropy are used to optimize the eigenmode function of the original signal in order to extract the main signal components and reduce the influence of noise, and then the Hilbert marginal spectrum is used to compute the energy of the optimized signal and determine the damage factor; finally, the array of the damage factor is expanded into a matrix and divided into two groups according to the orthogonal angle, and the matrix of the damage factor within a group the damage factor array is expanded into a matrix and divided into two groups according to the orthogonal angle, and the damage factor matrices within the groups are added together and then multiplied between the groups to obtain the final damage image. The experimental results show that the maximum localization error of single damage is 2.3 mm, and the localization error of multi-damage is 12.5 mm, and the efficiency of C-scanning is improved by 168.9% compared with point-by-point C-scanning. The method proposed in this paper can effectively improve the inspection efficiency and multi-damage localization accuracy of large-size specimens.