Abstract: The Babbitt Alloy Steel composite material is compounded by Babbitt Alloy and steel. The composition techniques are mainly rolling, welding and pouring burning. In the common factory, centrifugal casting and plane casting are acceptable by most mills. The quality of composite layer means the degree of binding of steel and the interface of Babbitt Alloy. The bad quality always cause axis burning, even broken. Therefore, composite layer inspection is very important. At present, longitudinal wave reflection method in ultrasonic testing is recognized widely. It can meet the application requirement basically provided that the exiting standards and products specification are reviewed and the quality of composite layer is inspected by ultrasonic testing.