The corrosion damage of aircraft structure can significantly reduce the safety performance of aircraft structure and endanger the flight safety. In this paper, an aircraft structure corrosion damage probability reconstruction algorithm based on guided wave is proposed to monitor the corrosion damage of aircraft structures. Targeted at structurally real corrosion damage, in this paper, the correlation between the Lamb wave reference signal and the monitoring signal is characterized by the spectrum amplitude difference damage index and used as the image reconstruction parameter in the reconstruction algorithm for probability inspection of damage (RAPID). According to the imaging results of the RAPID method, a fusion damage index method is proposed to evaluate the corrosion depth, and the structural corrosion damage measured by the ultrasonic C-scan system is compared with the above method. The experimental results show that the proposed method can effectively locate the corrosion damage and evaluate the corrosion depth.