Piezoelectric guided wave health monitoring, based on bonded PZT sensors, has garnered increasing attention in engineering applications. However, the environmental conditions in engineering—such as temperature, load, and calendar life—significantly impact the bonding properties of PZT sensors. This degradation of bonding properties directly affects the quality of the piezoelectric guided wave signal, thereby influencing the monitoring effectiveness. Since the bonding layer of PZT sensors is challenging to detect directly, an evaluation of PZT sensor bonding is essential. In this study, we analyze the guided wave, impedance, and strain data from PZT sensors under static and fatigue loads through element-level tests. We discover that the degradation of the adhesive layer simultaneously causes changes in guided waves, impedance, and strain. As the adhesive layer degrades, the amplitude of the guided wave decreases, the amplitude of the impedance's real part increases while the corresponding frequency decreases, and the strain transmissivity also varies. This indicates that the degradation of the PZT adhesive layer can be detected. In practical engineering, the sensor's bonding performance can be evaluated using impedance, strain, and other parameters to determine the need for PZT sensor reinstallation, thus enhancing the effectiveness of PZT piezoelectric guided wave health monitoring. This method offers significant guidance for evaluating the effectiveness of PZT sensors in engineering services.