Abstract: The tube sheet of the heat exchanger is a pore plate. The complex manufacturing process causes the plate to easily contain many kinds of defects. In addition, the joints between tube sheet and tubes are difficult to detect. To overcome the problem mentioned above, acoustic emission(AE) testing technology is used for its ability on structure testing. The sensors are connected with heat exchange tubes with special wave guide rods, and the array arrangement is referred to the results of attenuation measurement. Acoustic emission testing is carried out in two cycle hydrostatic test of shell side. After the analysis of different pressure maintaining stages signals with zone location method, taking AE signal activity and intensity into account, the AE testing and evaluation method of tube sheet is established. With this method, the grade of tube sheet can be identified.