Abstract:First, add a lower voltage to the sample of carbon fiber-reinforced concrete(CFRC) to create a Joule effect on this sample, which is a composite with some defects, by making use of this CFRC material's good electric conductivity. As the Joule effect caused some temperature differences on the surface of this sample, the second step it to inspect this sample with the method of infrared thermograph, which won't cause any damage to the testing sample. Finally, make a theoretical analysis on the tested data. The result shows: when the materials have some flaws of the same depth, we found the difference of temperature of the material with a smaller resistance is bigger compared with that of the material with a bigger resistance; when the materials share the same resistance, we found the depth flaws also have an effect on the difference of temperature on the surfaces. This result provides some theoretical and experimental proofs for further studies on methods of inspecting composite material for defects.