Abstract: Considering the difficulties of assessing fracture field by the single-parameter J-integral, the double-parameter JQ criterion, which is more adaptive to welded joints, is presented in this paper. This criterion is discussed and optimized in order to be easily applied in practice. By FEM, it proves that this optimized method could critically express the fracture properties of welded joints. Therefore, this method can be regarded as a better way to assess the properties of welded joints in engineering practice.