Abstract: Reinforced concrete is the most widely used building materials in the world. Changes in the external environment shall cause changes in internal steel corrosion and ultimately affect the overall component life. In this paper, the corrosion process of reinforced concrete is made by simulating and accelerating the internal steel corrosion process. The corrosion degree of the steel in concrete is measured and analyzed by three-dimensional industrial CT. The thickness of the corrosion layer is measured and the results of industrial CT are verified by anatomy and metallographic analysis. The results show that the industrial three-dimensional CT detection technology can realize the non-destructive testing and accurate measurement of the corrosion of steel bars in concrete.