Abstract: In order to meet the needs of dynamic monitoring for Q345R steel in industrial applications, acoustic emission (AE) test technology was proposed to characterize and quantitatively evaluate the damage process. Through the establishment of tensile test and AE test system, standard tensile experiments are tested. The characteristic parameters of acoustic emission signals are extracted, and then by referring to the tensile loading chart, the characteristic parameters course diagram, the analysis of the cumulative quantity and quantitative evaluation are respectively studied. The experimental results show that the two parameters analysis methods can all characterize the mechanical behavior of tensile damage process, and accumulation analysis can be more accurate and clear demarcation point of the mechanical behavior of each stage, which can provide a reference basis for the quantitative evaluation of materials.