Abstract: According to the acoustic characteristic of the two layers metal shell bonded structure, nondestructive testing of the steel and plumbum bonded structure by using longitudinal multi-echo refection method and transit method were studied. After analyzing its advantages and disadvantages, the steel-Pb bonded samples were designed and tested by two kinds of testing methods. Compared with the anatomized bonded interface, the test results showed that the two testing methods both could be used to detect the defects in the metal bonds.