Abstract <p>Cracks, spalling, cavities and other damages occur in the process of long-term service of concrete, so that the bearing capacity of the building decreases, which needs to be reinforced by the adhesive steel plate reinforcement method. However, debonding phenomenon can occur at the interface between steel plate and concrete, which affects the overall stiffness and load carrying capacity of the structure, so debonding detection at the steel-concrete interface is particularly important. In this paper, a reference-free Lamb wave-based identification detection method for steel plate-concrete debonding is proposed, in which the Hilbert energy spectrum is used as a damage factor. The method does not require a preset reference signal, which is obtained by comparing the debonding signals. Firstly, the simulation is carried out by finite element software, the circular sensor array is arranged on the surface of the steel plate, and each sensor acts as excitation and reception, the Hilbert energy spectrum of the signal is obtained, the damage coefficient is calculated, the probabilistic imaging algorithm is utilized to realize the localization of the debonding position and the imaging, and finally the simulation is verified by experiments. The results show the feasibility of the method in debonding identification detection.</p>