Abstract: The application of ultrasonic testing technology in the evaluation of lithium-ion batteries is attracting growing attention. With the continuous advancement of battery technology, ensuring safety and performance has become increasingly critical. As a non-destructive testing method, ultrasonic testing can effectively characterize battery material properties, detect internal defects, and assess both the state of charge (SOC) and state of health (SOH). By analyzing the reflection and transmission behavior of ultrasonic waves propagating through battery materials, crucial information about the internal microstructure and electrochemical performance can be obtained. This review summarizes recent advances in ultrasonic testing for lithium-ion battery evaluation, covering its fundamental principles, representative applications, and future research directions.