Abstract: An ultrasonic scanning device includes at least one pair of cylindrical rollers. The axes of each pair of cylindrical rollers are parallel to each other. A liquid for transmitting the ultrasound is stored in each cylindrical roller. In use, a pair of cylindrical rollers rotate around their respective axes in reverse directions, the test subject passes between the pair of cylindrical rollers and is tested by ultrasound. The ultrasonic scanning device can be applied in the field of lithium-ion battery testing. The internal flaws and health status of the lithium-ion battery can be determined by acquiring an ultrasonic image in the test subject. The device of the present invention has a simple structure and an ingenious conception, and is ready-to-use and less expensive, which is successfully applied in the field of lithium-ion battery testing.