The absorbing coating covered in the surface of equipment is apt to have the damage of abrasion, bulging, aging after used for a long period of time. In this paper, the three damage modes and its influence on absorbing performance are investigated by the reflectivity and phase measurement and microwave imaging. The above three kinds of damage samples of radar absorbing coating and infraredradar absorbing coating are made, reflectivity and phase are measured with arch method, and microwave images are built by the radar scattering imaging system for stealthy target. With the comparison of the experimental results and qualitative analysis, it is found that the all of the damage on coating make the absorbing performance deteriorate, its corresponding absorbing band become narrow, and a shift due to the variation in structure and composition of absorbing materials. However, the wear damage mode has the most serious impact on the two kinds of microwave absorbing coatings, resulting in a sharp decline in the absorption capacity