Abstract: Aiming at the titanium alloy of new pattern steam generator unit, this paper proposed the use of AE technology to monitor the material performance during the manufactory. Using the AE monitoring system to monitor the whole process of the elongate test of standard tensile sample and analyze the obtained data, the AE characteristics of unit subassembly material and sensitivity of AE monitoring system is obtained.The validity of analytic result of standard sample is verified by the result from the tension test on tube-board tensile sample, and thus the feasibility of the use of AE technology to monitor steam generator unit subassembly on hydraulic pressure experimentation is affirmed.