Abstract: Reinforced concrete tower is an important carrier for power transmission. In the long-term operation process, the internal steel bars are prone to corrosion due to environmental influences, which in turn affects their mechanical strength. For purpose of exploring efficient and practical corrosion evaluation method, a corrosion detection method for reinforced concrete tower based on microwave transmission characteristics was proposed in this paper. The microwave detection test of reinforced concrete model was carried out, and the validity of the microwave corrosion detection numerical simulation method was verified by comparing the test with the numerical simulation results. The numerical simulation model of corrosion microwave detection for the actual reinforced concrete tower was established. The influences of lift-off distance, waveguide placement and microwave frequency on the detection results were analyzed, and the optimal detection parameters were determined. The detection effects of towers corrosion with different depths, lengths and positions were analyzed by rotating scanning and moving scanning. The results show that the corrosion state of steel bar can be obtained according to the variation law of microwave scattering parameters. The peak value for the variation of transmission coefficient is proportional to the corrosion depth, and the corrosion depth and length can be reflected by its peak and amplitude variation area. The research can provide a new method for the corrosion detection of steel bars in concrete towers.