The weld-bonding test was carried out based on Box-Behnken Design response surface method， the acoustic emission signals in the stretching process of weld-bonding， spot-welding and adhesive joints were collected， and the signal was decomposed and reconstructed by wavelet packet. The weld nugget failure fracture was analyzed based on the hits history diagram， and the damage models of three kinds of joints were established through the cumulative hits. The results show that the three types of joints have abundant acoustic emission signals in the yield stage and fracture stage. Adhesive layer failure and weld nugget failure can be distinguished by acoustic emission signal characteristics. And the failure frequency of the adhesive layer is mainly concentrated in 0 to 62.5 kHz. When the weld nugget fails， the frequency is mainly concentrated in 31.25 to 281.25 kHz.The acoustic emission hits history diagram can reflect the failure process of the nugget on the whole. The established damage model can better characterize the damage state of the specimen.