Aimed to multifarious surface conditions of aircraft composites, a research was conducted to apply thermography technology to composites with common aeronautic surfaces. A surface condition reference specimen with simulated defects was designed and manufactured, which included 8 kinds of common aircraft composites surfaces. NDTherm® NT thermography system was applied to conduct tests. For the composites part with same material and different surface conditions, the defect test results have obvious differences. And the results had been discussed from aspects of the detection sensitivity, copper net, surface materials and surface roughness.