Abstract: Aiming at the defect detection of pressure vessels in the nuclear reactor environment, in order to prevent the inspectors from being exposed to radiation doses for a long time, the acoustic emission(AE) detection technology is used to carry out the experimental research of pressure vessel simulation defect location technology. According to the different characteristics of acoustic emission source, the TDOA method and attenuation location method are adopted. The important parameters of the two methods are calibrated through experiments, and the positioning of simulation acoustic emission source is realized. The accuracy of the positioning results is verified through experiments, and it is concluded that both TDOA method and attenuation location method are suitable for sudden AE source, while attenuation localization method can be used for continuous AE source. The maximum error of localization is less than 10% of the distance between the two sensors.