Through carrying out ultrasonic guided wave experiments in steel strands with different level corrosion, corrosion indicators were established by calculating the eigenvectors of wavelet packet energy spectrum from the measured guide wave.The results indicated that the wavelet packet energy spectrum changed obviously and the corrosion indicators increased linearly with the increasing of corrosion degree.The sensibility of corrosion indicators was superior when the excitation source located at the lateral of steel strands, and the K-value from end section was 51.35% of strands side and the determination coefficient reduced 6.4% meanwhile.Corrosion indicators possessed good performance in anti-noise capability, which reduced 5.97% when the signal-noise ratio reached 10 dB and still reached 0.51 as the signal-noise down to 0 dB.Corrosion indicators were affected by guide wave propagation distance and their sensibility brought down slightly and appeared great fluctuation in low corrosion degree with the increasing of propagation distance.