Abstract: With the rapid increase of retired electric vehicles, the hierarchical recycling and reuse of lithium-ion power batteries have promising development prospects. Detection methods based on electrical parameters are difficult to identify potential abnormal conditions in local areas of single cells. However, ultrasound parameters can detect internal material uniformity of prismatic aluminum-shell power batteries in specific regions, further screening batteries suitable for hierarchical utilization or requiring scrap recycling. In this study, an ultrasonic bulk wave test system was first constructed, and this system performed a charge-discharge experiment on prismatic aluminum-shell lithium-ion batteries under complex working conditions, aiming to explore the propagation law of ultrasonic bulk waves in square aluminum-shell lithium-ion batteries. The experimental conditions included low and high discharge rates, as well as step-change temperature phenomena. Subsequently, cross-wavelet transform analysis was applied to the results of low-rate charge-discharge experiments to verify the rationality of the signal excitation frequency. Finally, a hierarchical screening test system for square aluminum-shell batteries was constructed, and multi-element detection was carried out on different batches of a certain type of commercial battery with known capacity. This aimed to explore the local ultrasonic characteristics of commercial battery packs under different battery health conditions. Following this, uniformity analysis was conducted on the arrays of the entire battery, and the experimental results could effectively classify three batches of batteries as in-service, nearing retirement, and suitable for hierarchical utilization after retirement. This study laid the foundation for non-destructive hierarchical classification of power batteries.