The concretefilledsteeltubular (CFST) structures make full use of the advantages of both steel and concrete, has superior mechanical properties, and has been widely used in highrise buildings and large bridges. However, the interface debonding defects between the steel tube and concrete can have a negative effect on the structural mechanical properties. It is important to effectively detect the concealed interface debonding defects, and this is easy to implement based on the same side piezoelectric ceramic sheet driving and surface wave measurement. In this paper, in order to demonstrate the feasibility of the surface debonding detection approach and to investigate its mechanism, the CFST members with different interface debinding detections and PZT patches as actuator and sensor are numerically modeled and analyzed with ANSYS considering the coupling effect between PZT and CFST member and the piezoelectric effect of PZT patches. The numerical simulation results show that the signal amplitude under the interface debonding defect conditions is larger than that under healthy conditions, and the damage degree is positively correlated with the signal amplitude change. The larger the damage scale, the larger the signal amplitude. The proposed method for detecting the interface debonding defects based on surface wave measurement is effective.