Abstract: This study is based on EBSD (Electron Backscattered Diffraction) spectra to simulate and model austenitic stainless steel welds, exploring in depth the propagation patterns of array signals in austenitic stainless steel welds, as well as the reflection, scattering, and transmission patterns of ultrasonic waves at defects and interfaces. The research results indicate that due to the large difference in acoustic impedance and the influence of angle on the echo of crack defects, a reasonable acoustic deflection angle should be selected during detection to improve the detection ability; Pore defects have high acoustic impedance and high echo amplitude, which can be used to locate their upper surface position and characterize their size through echoes; As the size of slag inclusion defects increases, the reflected echoes will separate, and the size needs to be determined by combining the echoes and duration; When the root opening defect is vertically incident, the upper tip echo is strong and the lower tip echo is weak. The oblique incidence method should be used and the probe position should be changed to improve the detection rate. The results of this study can provide important references for the development of austenitic stainless steel weld detection processes, and help to formulate more effective detection processes and quality control measures.