Abstract: To determine the acoustic emission intensity threshold of 0Cr18Ni9Ti austenitic stainless steel, acoustic emission technology was used to monitor signals throughout material tensile tests, including yield and strengthening stages. Four types of specimens were tested: defect-free base metal, defective welds, defect-free welds, and V-notch defective base metal, loaded under uniaxial tension until fracture, with linear positioning for signal discrimination filtering. Through signal collection from various specimen fracture tests, acoustic emission mechanisms during plastic deformation and crack propagation were analyzed, obtaining material characterization acoustic emission intensity threshold ranges. Results showed that defective weld specimens exhibited the most significant acoustic emission response, with amplitude responses markedly higher than other specimen types, consistent with theoretical expectations and confirming acoustic emission technology’s effectiveness for active defect detection.